title

A* Pathfinding Algorithm (Coding Challenge 51 - Part 1)

description

In this multi-part coding challenge, I attempt an implementation of the A* Pathfinding Algorithm to find the optimal path between two points in a 2D grid. Code: https://thecodingtrain.com/challenges/51-a-pathfinding-algorithm
đģ Github Repo: https://github.com/CodingTrain/AStar
đšī¸ p5.js Web Editor Sketch: https://editor.p5js.org/codingtrain/sketches/ehLjdFpat
Other Parts of this Challenge:
đē A* Algorithm - Part 2: https://youtu.be/EaZxUCWAjb0
đē A* Algorithm - Part 3: https://youtu.be/jwRT4PCT6RU
đĨ Previous video: https://youtu.be/QHEQuoIKgNE?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH
đĨ Next video: https://youtu.be/l__fEY1xanY?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH
đĨ All videos: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH
References:
đ Artificial Intelligence: A Modern Approach: http://aima.cs.berkeley.edu/
đ A* Search Algorithm on Wikipedia: https://en.wikipedia.org/wiki/A*_search_algorithm
đģ Online demo: https://codingtrain.github.io/AStar/
Live Stream Archive:
đ´ Live Stream #72: https://www.youtube.com/watch?v=S4yQYiAECnM&t=34m50s
Related Coding Challenges:
đ #10 Maze Generator: https://youtu.be/HyK_Q5rrcr4
đ #162 Self Avoiding Walk: https://youtu.be/m6-cm6GZ1iw
Timestamps:
0:00:00 Introduction
0:01:26 A* Pathfinder
0:09:39 Coding a Grid
0:13:09 A* Pathfinder Algorithm
0:22:07 Choosing Best Available Path
0:27:05 Finding New Nodes
0:38:30 Adding Heuristic
0:41:50 Tracing Back
0:46:49 Using Better Heuristics
Editing by Mathieu Blanchette
Animations by Jason Heglund
Music from Epidemic Sound
đ Website: http://thecodingtrain.com/
đž Share Your Creation! https://thecodingtrain.com/guides/passenger-showcase-guide
đŠ Suggest Topics: https://github.com/CodingTrain/Suggestion-Box
đĄ GitHub: https://github.com/CodingTrain
đŦ Discord: https://discord.gg/hPuGy2g
đ Membership: http://youtube.com/thecodingtrain/join
đ Store: https://standard.tv/codingtrain
đī¸ Twitter: https://twitter.com/thecodingtrain
đ¸ Instagram: https://www.instagram.com/the.coding.train/
đĨ Coding Challenges: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6ZiZxtDDRCi6uhfTH4FilpH
đĨ Intro to Programming: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6Zy51Q-x9tMWIv9cueOFTFA
đ p5.js: https://p5js.org
đ p5.js Web Editor: https://editor.p5js.org/
đ Processing: https://processing.org
đ Code of Conduct: https://github.com/CodingTrain/Code-of-Conduct
This description was auto-generated. If you see a problem, please open an issue: https://github.com/CodingTrain/thecodingtrain.com/issues/new
#aalgorithm #pathfinding #heuristic #p5js #javascript

detail

{'title': 'A* Pathfinding Algorithm (Coding Challenge 51 - Part 1)', 'heatmap': [{'end': 1767.544, 'start': 1722.448, 'weight': 1}], 'summary': 'Delves into a* pathfinding algorithm, detailing troubleshooting process, discussing optimal pathfinding, a* implementation, open and closed set in algorithm, javascript array manipulation, and optimizing the algorithm for pathfinding.', 'chapters': [{'end': 36.298, 'segs': [{'end': 52.673, 'src': 'embed', 'start': 23.555, 'weight': 0, 'content': [{'end': 25.835, 'text': 'It took me 2 and 1 half hours to sort this out.', 'start': 23.555, 'duration': 2.28}, {'end': 26.876, 'text': 'I had a lot of bugs.', 'start': 25.855, 'duration': 1.021}, {'end': 29.636, 'text': "But what you're going to watch is a little bit shorter.", 'start': 27.696, 'duration': 1.94}, {'end': 30.476, 'text': "Some of it's edited out.", 'start': 29.736, 'duration': 0.74}, {'end': 34.858, 'text': "If you want to watch the full archive of the live stream, you can find a link to that in this video's description.", 'start': 30.496, 'duration': 4.362}, {'end': 36.298, 'text': 'This is the final result.', 'start': 35.158, 'duration': 1.14}, {'end': 44.105, 'text': "what i'm using is an algorithm to find the optimal path from the top left corner of the screen to the bottom right corner of the screen,", 'start': 36.678, 'duration': 7.427}, {'end': 48.87, 'text': "going around some obstacles, and you can see here this is that path, and there's a lot of pieces to this.", 'start': 44.105, 'duration': 4.765}, {'end': 52.673, 'text': 'the video is going to be in two parts, so the first part of the video,', 'start': 48.87, 'duration': 3.803}], 'summary': 'The algorithm found the optimal path after 2.5 hours, with edited video available.', 'duration': 29.118, 'max_score': 23.555, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k23555.jpg'}], 'start': 1.786, 'title': 'A star pathfinding algorithm', 'summary': "Delves into the a star pathfinding algorithm, detailing the presenter's 2.5-hour troubleshooting process to resolve bugs, which led to a shortened edited video.", 'chapters': [{'end': 36.298, 'start': 1.786, 'title': 'A star pathfinding algorithm', 'summary': 'Explores the a star pathfinding algorithm, with the presenter admitting to facing bugs and taking 2.5 hours to resolve the challenges, resulting in a shortened edited video.', 'duration': 34.512, 'highlights': ['The presenter took 2.5 hours to resolve the bugs in implementing the A star pathfinding algorithm.', 'The presenter admits to the challenges faced, resulting in a messy recording that was edited for brevity.']}], 'duration': 34.512, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1786.jpg', 'highlights': ['The presenter took 2.5 hours to resolve the bugs in implementing the A star pathfinding algorithm.', 'The presenter admits to the challenges faced, resulting in a messy recording that was edited for brevity.']}, {'end': 463.535, 'segs': [{'end': 77.83, 'src': 'embed', 'start': 52.673, 'weight': 2, 'content': [{'end': 57.958, 'text': "the only thing that i'm going to do is look at how to make the optimal path from the top left to the bottom right,", 'start': 52.673, 'duration': 5.285}, {'end': 61.502, 'text': 'with no obstacles and not being allowed to go diagonally,', 'start': 57.958, 'duration': 3.544}, {'end': 68.825, 'text': 'and then That video will finish and the second part of the video will show you how to add diagonals and how to add obstacles.', 'start': 61.502, 'duration': 7.323}, {'end': 72.027, 'text': 'And so enjoy, watch.', 'start': 69.946, 'duration': 2.081}, {'end': 77.83, 'text': "If you don't see the second half published as part of my feed, go check this video's description.", 'start': 72.247, 'duration': 5.583}], 'summary': 'The video demonstrates finding the optimal path from top left to bottom right without obstacles and diagonals, with a follow-up on adding diagonals and obstacles.', 'duration': 25.157, 'max_score': 52.673, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k52673.jpg'}, {'end': 134.442, 'src': 'embed', 'start': 94.235, 'weight': 0, 'content': [{'end': 96.037, 'text': 'The A star algorithm is a search algorithm,', 'start': 94.235, 'duration': 1.802}, {'end': 104.204, 'text': "meaning there's some space of possibilities and you want to search through that space for a particular needle in a haystack, so to speak.", 'start': 96.037, 'duration': 8.167}, {'end': 107.446, 'text': 'a solution, an optimal solution out of all possible solutions.', 'start': 104.204, 'duration': 3.242}, {'end': 110.189, 'text': 'And typically speaking, there are a lot of search algorithms.', 'start': 107.847, 'duration': 2.342}, {'end': 111.15, 'text': "Maybe I'll come back to others.", 'start': 110.209, 'duration': 0.941}, {'end': 115.593, 'text': 'A star is typically applied to a pathfinding kind of search problem.', 'start': 111.51, 'duration': 4.083}, {'end': 117.655, 'text': "So let's talk about what I mean by pathfinding.", 'start': 115.833, 'duration': 1.822}, {'end': 120.176, 'text': "Here's one scenario.", 'start': 119.376, 'duration': 0.8}, {'end': 131.741, 'text': 'Incidentally, a scenario that A star can actually be applied to is trains like how to make an optimal path of freight trains between a whole bunch of cities to get stuff from one city to another.', 'start': 120.557, 'duration': 11.184}, {'end': 134.442, 'text': "So let's sort of imagine driving or cars and cities.", 'start': 131.781, 'duration': 2.661}], 'summary': 'The a star algorithm is a search algorithm used for pathfinding, including finding optimal paths for freight trains between cities.', 'duration': 40.207, 'max_score': 94.235, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k94235.jpg'}, {'end': 246.247, 'src': 'embed', 'start': 214.25, 'weight': 1, 'content': [{'end': 217.632, 'text': "It works, and it will find you the optimal one, but it's not super efficient.", 'start': 214.25, 'duration': 3.382}, {'end': 223.716, 'text': "So A star is, because it takes a long time, like this doesn't take that long, but if there are like thousands of nodes, it takes a really long time.", 'start': 217.972, 'duration': 5.744}, {'end': 230.761, 'text': "The A star algorithm is very similar to Dijkstra's algorithm, but it uses a concept known as heuristics.", 'start': 224.377, 'duration': 6.384}, {'end': 233.86, 'text': "I have no idea if I'm going to be able to spell this.", 'start': 232.213, 'duration': 1.647}, {'end': 237.345, 'text': 'Heuristics Heuristics is like a really fancy word.', 'start': 234.844, 'duration': 2.501}, {'end': 239.525, 'text': "When you use it, you sound like you know what you're doing.", 'start': 237.525, 'duration': 2}, {'end': 246.247, 'text': "But it's really just a word for describing a, I would say, one way to think about it is an educated guess.", 'start': 240.605, 'duration': 5.642}], 'summary': 'A* algorithm is efficient but slower with thousands of nodes; uses heuristics for educated guessing.', 'duration': 31.997, 'max_score': 214.25, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k214250.jpg'}], 'start': 36.678, 'title': 'Optimal path finding algorithm and a-star algorithm', 'summary': "Discusses the use of an algorithm to find the optimal path from top left to bottom right of a screen, covering pathfinding without obstacles, addition of diagonal movement and obstacles, and introduces the a-star algorithm, comparing it with dijkstra's algorithm and emphasizing heuristics for efficiency.", 'chapters': [{'end': 72.027, 'start': 36.678, 'title': 'Optimal path finding algorithm', 'summary': 'Discusses using an algorithm to find the optimal path from the top left to the bottom right of the screen, with the first part covering the path without obstacles or diagonal movement, and the second part addressing the addition of diagonal movement and obstacles.', 'duration': 35.349, 'highlights': ['The video is divided into two parts, the first part focuses on making the optimal path from the top left to the bottom right with no obstacles and no diagonal movement.', 'The second part of the video will demonstrate how to add diagonal movement and obstacles to the optimal path finding algorithm.']}, {'end': 463.535, 'start': 72.247, 'title': 'A-star algorithm in javascript', 'summary': "Introduces the a-star algorithm, a search algorithm used for pathfinding, particularly in scenarios like optimal freight train paths between cities. it compares a-star with dijkstra's algorithm, highlighting the use of heuristics to skip checking possibilities and improve efficiency.", 'duration': 391.288, 'highlights': ['A-star algorithm is a search algorithm used for pathfinding The A-star algorithm is used to search through a space of possibilities for an optimal solution, particularly in pathfinding scenarios like finding the optimal path for freight trains between cities.', "Comparison of A-star with Dijkstra's algorithm The A-star algorithm is compared with Dijkstra's algorithm, with a focus on A-star's use of heuristics to skip checking possibilities and improve efficiency, making it faster and more efficient than Dijkstra's algorithm, especially when dealing with a large number of nodes.", "Use of heuristics to improve efficiency A-star algorithm uses heuristics, which are educated guesses, to skip checking many possibilities, thereby improving the algorithm's efficiency and speed, ensuring that the heuristic does not overestimate the time to avoid suboptimal results."]}], 'duration': 426.857, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k36678.jpg', 'highlights': ['A-star algorithm uses heuristics to skip checking many possibilities, improving efficiency.', "A-star algorithm is faster and more efficient than Dijkstra's algorithm, especially with a large number of nodes.", 'The video demonstrates adding diagonal movement and obstacles to the optimal pathfinding algorithm.', 'A-star algorithm is used for pathfinding, particularly in scenarios like finding the optimal path for freight trains between cities.', 'The video focuses on making the optimal path from top left to bottom right with no obstacles and no diagonal movement.']}, {'end': 846.563, 'segs': [{'end': 576.485, 'src': 'embed', 'start': 552.128, 'weight': 1, 'content': [{'end': 558.372, 'text': 'So this is a generic way of finding a path through any given pixel space, because pixel spaces are just grids.', 'start': 552.128, 'duration': 6.244}, {'end': 564.176, 'text': 'And we could do things like then add a sort of steering agent to follow the path or that sort of thing.', 'start': 558.813, 'duration': 5.363}, {'end': 567.419, 'text': 'Or we could kind of create a nontraditional grid of network map like this.', 'start': 564.437, 'duration': 2.982}, {'end': 571.902, 'text': "But I think it's going to be a classic implementation and demonstration is using a system like this.", 'start': 567.619, 'duration': 4.283}, {'end': 574.123, 'text': "And if this is a full grid, I just didn't draw out all the pieces.", 'start': 572.062, 'duration': 2.061}, {'end': 576.485, 'text': "So that's what I'm going to do.", 'start': 574.403, 'duration': 2.082}], 'summary': 'This is a discussion about finding a path through a pixel space, with potential applications including adding a steering agent or creating a nontraditional grid or network map.', 'duration': 24.357, 'max_score': 552.128, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k552128.jpg'}, {'end': 624.892, 'src': 'embed', 'start': 597.065, 'weight': 2, 'content': [{'end': 600.128, 'text': "And I'm going to use some Java syntax.", 'start': 597.065, 'duration': 3.063}, {'end': 606.453, 'text': "And you know what I'm going to do, too, is I'm going to say I want to have some variables that say there's always going to be, let's start small.", 'start': 600.188, 'duration': 6.265}, {'end': 609.075, 'text': "There's going to be five columns and five rows.", 'start': 606.473, 'duration': 2.602}, {'end': 611.137, 'text': 'So the grid is five by five.', 'start': 609.415, 'duration': 1.722}, {'end': 615.929, 'text': 'So two-dimensional arrays are sort of goofy in JavaScript.', 'start': 612.748, 'duration': 3.181}, {'end': 624.892, 'text': 'What I ultimately want to do is I want to say things like grid 0, comma, grid index 0.', 'start': 615.949, 'duration': 8.943}], 'summary': 'Using java syntax to create a 5x5 grid with two-dimensional arrays.', 'duration': 27.827, 'max_score': 597.065, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k597065.jpg'}, {'end': 767.831, 'src': 'embed', 'start': 740.174, 'weight': 3, 'content': [{'end': 744.116, 'text': "And I'll talk about some things maybe later at the end that we'll see that we made more efficient.", 'start': 740.174, 'duration': 3.942}, {'end': 748.439, 'text': 'But I want to make each spot in the grid an object.', 'start': 744.477, 'duration': 3.962}, {'end': 750.881, 'text': "And I'm going to call it a cell, a spot.", 'start': 748.479, 'duration': 2.402}, {'end': 753.061, 'text': "Let's call it a spot.", 'start': 752.401, 'duration': 0.66}, {'end': 754.322, 'text': "I don't know what a good name for this would be.", 'start': 753.101, 'duration': 1.221}, {'end': 760.286, 'text': 'So what I need is a constructor function to create an object.', 'start': 755.403, 'duration': 4.883}, {'end': 767.831, 'text': 'So every object will have a f value, a g value, and an h value.', 'start': 760.646, 'duration': 7.185}], 'summary': 'Each grid spot will be an object with f, g, and h values.', 'duration': 27.657, 'max_score': 740.174, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k740174.jpg'}, {'end': 819.685, 'src': 'embed', 'start': 787.764, 'weight': 0, 'content': [{'end': 789.165, 'text': 'So now I have a grid of spots.', 'start': 787.764, 'duration': 1.401}, {'end': 792.048, 'text': "And now what I need to do now, here's the thing.", 'start': 790.026, 'duration': 2.022}, {'end': 797.889, 'text': 'The A star algorithm, by definition, Is a loop.', 'start': 792.548, 'duration': 5.341}, {'end': 802.552, 'text': "it's trying a lot of possibilities until it gets to the solution and then it's done.", 'start': 797.889, 'duration': 4.663}, {'end': 809.137, 'text': 'So what I want to do is have my example demonstrate and animate the process.', 'start': 802.552, 'duration': 6.585}, {'end': 812.9, 'text': "So I'm going to do something a little bit different than probably what's found in that Wikipedia pseudocode.", 'start': 809.137, 'duration': 3.763}, {'end': 819.685, 'text': "pseudocode I'm using I forgot to mention I'm using a JavaScript framework called p5 and, as a set, p5 asks you to write a setup function,", 'start': 812.9, 'duration': 6.785}], 'summary': 'Implementing a star algorithm with demonstration using javascript framework p5', 'duration': 31.921, 'max_score': 787.764, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k787764.jpg'}, {'end': 848.385, 'src': 'embed', 'start': 823.428, 'weight': 4, 'content': [{'end': 829.431, 'text': "it's an animation loop, what you would do normally with request, animation frame or something like that with native JavaScript.", 'start': 823.428, 'duration': 6.003}, {'end': 832.452, 'text': "So what I'm going to do is I'm going to use the draw loop as the loop.", 'start': 829.771, 'duration': 2.681}, {'end': 842.88, 'text': "So if I go back to this particular page, We can see here, where is that loop? There's this loop here, while open set is not empty.", 'start': 832.732, 'duration': 10.148}, {'end': 846.563, 'text': "So this is it's doing this thing to solve the problem.", 'start': 843.1, 'duration': 3.463}, {'end': 848.385, 'text': "So here's the thing.", 'start': 847.044, 'duration': 1.341}], 'summary': 'Using a draw loop to solve a problem in javascript animation.', 'duration': 24.957, 'max_score': 823.428, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k823428.jpg'}], 'start': 464.116, 'title': 'Implementing a* algorithm', 'summary': 'Discusses implementing the a* search algorithm to find the optimal path through a grid of cities, considering obstacles, and potential applications in pixel spaces. it also covers the creation of a 2d array, initializing each spot with a cost, and implementing a loop for the a* algorithm using javascript, with a focus on ease and readability rather than optimal efficiency.', 'chapters': [{'end': 571.902, 'start': 464.116, 'title': 'Implementing a* search algorithm', 'summary': 'Discusses implementing the a* search algorithm to find the optimal path through a grid of cities, considering obstacles, and potential applications in pixel spaces.', 'duration': 107.786, 'highlights': ['The A* search algorithm is being implemented to find the optimal path through a grid of cities, considering obstacles.', 'The system uses a node-based type of map, representing a grid of cities where each city is connected to every city around it.', "The algorithm's potential application in pixel spaces is highlighted, with the mention of adding a steering agent to follow the path."]}, {'end': 846.563, 'start': 572.062, 'title': 'Implementing a* algorithm in javascript', 'summary': 'Covers the creation of a 2d array, initializing each spot with a cost, and implementing a loop for the a* algorithm using javascript, with a focus on ease and readability rather than optimal efficiency.', 'duration': 274.501, 'highlights': ['Creation of a 2D array with 5 columns and 5 rows in JavaScript, forming the basis for the A* algorithm implementation. The speaker creates a 2D array with 5 columns and 5 rows in JavaScript as the basis for the A* algorithm implementation.', 'Initialization of each spot in the grid with a cost, represented as an object containing f, g, and h values. The speaker initializes each spot in the grid with a cost, represented as an object containing f, g, and h values for the A* algorithm implementation.', 'Use of the draw loop for animating the A* algorithm process in JavaScript, deviating from the typical approach in Wikipedia pseudocode. The speaker deviates from the typical approach and uses the draw loop for animating the A* algorithm process in JavaScript, instead of following the Wikipedia pseudocode.']}], 'duration': 382.447, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k464116.jpg', 'highlights': ['The A* search algorithm is being implemented to find the optimal path through a grid of cities, considering obstacles.', "The algorithm's potential application in pixel spaces is highlighted, with the mention of adding a steering agent to follow the path.", 'Creation of a 2D array with 5 columns and 5 rows in JavaScript, forming the basis for the A* algorithm implementation.', 'Initialization of each spot in the grid with a cost, represented as an object containing f, g, and h values.', 'Use of the draw loop for animating the A* algorithm process in JavaScript, deviating from the typical approach in Wikipedia pseudocode.']}, {'end': 1497.642, 'segs': [{'end': 916.074, 'src': 'embed', 'start': 869.318, 'weight': 0, 'content': [{'end': 877.644, 'text': 'So the idea is that closed set stores a list of all the nodes that have finished being evaluated.', 'start': 869.318, 'duration': 8.326}, {'end': 881.366, 'text': "So this is everything that's done that you don't need to ever revisit.", 'start': 878.424, 'duration': 2.942}, {'end': 883.207, 'text': "That's going to be closed set.", 'start': 882.006, 'duration': 1.201}, {'end': 888.991, 'text': 'Open set are nodes that still need to be evaluated.', 'start': 883.668, 'duration': 5.323}, {'end': 890.692, 'text': 'We need to consider and evaluate them.', 'start': 889.251, 'duration': 1.441}, {'end': 892.013, 'text': "They're not closed yet.", 'start': 890.712, 'duration': 1.301}, {'end': 897.577, 'text': 'The algorithm is finished when open set is empty.', 'start': 892.934, 'duration': 4.643}, {'end': 899.158, 'text': "There's nothing left to be evaluated.", 'start': 897.597, 'duration': 1.561}, {'end': 902.601, 'text': "Okay, actually, that's not entirely right.", 'start': 900.399, 'duration': 2.202}, {'end': 904.403, 'text': 'So the algorithm is finished.', 'start': 903.482, 'duration': 0.921}, {'end': 906.805, 'text': "There's two ways the algorithm can finish.", 'start': 905.424, 'duration': 1.381}, {'end': 908.087, 'text': 'One is.', 'start': 907.386, 'duration': 0.701}, {'end': 913.272, 'text': "I'm going to be searching through nodes and if I ever arrive at the end, I'm finished, because I arrived at the end.", 'start': 908.087, 'duration': 5.185}, {'end': 914.793, 'text': 'I found the optimal path all the way there.', 'start': 913.272, 'duration': 1.521}, {'end': 916.074, 'text': "That's the way this algorithm is working.", 'start': 914.873, 'duration': 1.201}], 'summary': 'Algorithm evaluates nodes, finishes when open set is empty or optimal path is found.', 'duration': 46.756, 'max_score': 869.318, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k869318.jpg'}, {'end': 969.247, 'src': 'embed', 'start': 938.592, 'weight': 2, 'content': [{'end': 940.434, 'text': 'A closed set starts as empty.', 'start': 938.592, 'duration': 1.842}, {'end': 942.595, 'text': 'Open set starts with just one node.', 'start': 940.574, 'duration': 2.021}, {'end': 944.576, 'text': 'right at the beginning.', 'start': 943.476, 'duration': 1.1}, {'end': 949.478, 'text': 'the open set just has just the starting node.', 'start': 944.576, 'duration': 4.902}, {'end': 960.282, 'text': "so let's go into my code again and let's create I'm going to make some of these global variables just so we can kind of look at them in the console if we need to or evaluate them.", 'start': 949.478, 'duration': 10.804}, {'end': 961.502, 'text': 'closed set.', 'start': 960.282, 'duration': 1.22}, {'end': 969.247, 'text': "so I'm going to create two arrays open open list, open set, open set and closed set.", 'start': 961.502, 'duration': 7.745}], 'summary': 'Algorithm initializes open set with one node and an empty closed set.', 'duration': 30.655, 'max_score': 938.592, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k938592.jpg'}], 'start': 847.044, 'title': 'Algorithm open and closed set', 'summary': 'Explains the concept of open set and closed set in an algorithm, where open set stores nodes for evaluation, closed set stores finished nodes, and the algorithm finishes when the open set is empty, with the possibility of no solution if open set is empty and the end node is not reached.', 'chapters': [{'end': 1497.642, 'start': 847.044, 'title': 'Algorithm open and closed set', 'summary': 'Explains the concept of open set and closed set in an algorithm, where open set stores nodes for evaluation, closed set stores finished nodes, and the algorithm finishes when the open set is empty, with the possibility of no solution if open set is empty and the end node is not reached.', 'duration': 650.598, 'highlights': ['The algorithm finishes when the open set is empty, indicating that there are no nodes left to be evaluated, with the potential scenario of no solution if the end node is not reached.', "The closed set stores all the nodes that have finished being evaluated, indicating the nodes that don't need to be revisited.", 'The open set starts with just one node at the beginning and the closed set starts as empty, setting the initial conditions for the algorithm.', 'The process involves iterating through the open set to evaluate the nodes until the open set is empty, determining the completion of the algorithm.']}], 'duration': 650.598, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k847044.jpg', 'highlights': ['The algorithm finishes when the open set is empty, indicating no nodes left to be evaluated, with potential scenario of no solution if end node is not reached.', "The closed set stores all nodes finished being evaluated, indicating nodes that don't need to be revisited.", 'The open set starts with just one node at the beginning and the closed set starts as empty, setting the initial conditions for the algorithm.', 'The process involves iterating through the open set to evaluate the nodes until the open set is empty, determining the completion of the algorithm.']}, {'end': 1942.82, 'segs': [{'end': 1540.704, 'src': 'embed', 'start': 1497.662, 'weight': 0, 'content': [{'end': 1500.763, 'text': 'If you really want to test, if you really want to be sure, use the triple equals.', 'start': 1497.662, 'duration': 3.101}, {'end': 1503.383, 'text': "So if current is the end, we're done.", 'start': 1501.703, 'duration': 1.68}, {'end': 1511.666, 'text': 'Otherwise, what do I want to do? I want to add close set push current.', 'start': 1503.864, 'duration': 7.802}, {'end': 1516.31, 'text': 'And then I want to say open set remove current.', 'start': 1513.106, 'duration': 3.204}, {'end': 1518.453, 'text': 'This is not any actual real code.', 'start': 1516.591, 'duration': 1.862}, {'end': 1520.256, 'text': "So here's one of the tricky things.", 'start': 1518.794, 'duration': 1.462}, {'end': 1527.245, 'text': 'What I want to do is there is a function in JavaScript to add a particular object to an array.', 'start': 1520.696, 'duration': 6.549}, {'end': 1527.766, 'text': "That's push.", 'start': 1527.325, 'duration': 0.441}, {'end': 1534.68, 'text': "There is no function in JavaScript to just arbitrarily say, hey, this thing, if it's in the array, remove it.", 'start': 1529.056, 'duration': 5.624}, {'end': 1537.562, 'text': "And this is where I'm going to not do things so optimally.", 'start': 1535.36, 'duration': 2.202}, {'end': 1540.704, 'text': "But what I'm going to do is I need to find that object and remove it.", 'start': 1537.982, 'duration': 2.722}], 'summary': 'Use triple equals for testing in javascript and manipulate arrays with push and remove operations.', 'duration': 43.042, 'max_score': 1497.662, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1497662.jpg'}, {'end': 1615.149, 'src': 'embed', 'start': 1587.66, 'weight': 1, 'content': [{'end': 1591.042, 'text': 'add an index from the array and only want to delete that one array.', 'start': 1587.66, 'duration': 3.382}, {'end': 1598.808, 'text': "somebody in the I'm sure somebody can can tell me a better way to do it, but it'll work for right now.", 'start': 1591.042, 'duration': 7.766}, {'end': 1600.128, 'text': "maybe I'll come back and optimize that later.", 'start': 1598.808, 'duration': 1.32}, {'end': 1604.076, 'text': 'But why do I go through it backwards?', 'start': 1602.554, 'duration': 1.522}, {'end': 1610.063, 'text': "The reason why I go through it backwards is if I'm going through the array forwards and I delete something, then all the elements come back.", 'start': 1604.276, 'duration': 5.787}, {'end': 1612.626, 'text': "And I'm moving forwards, I could skip an element.", 'start': 1610.203, 'duration': 2.423}, {'end': 1613.607, 'text': 'So I want to go through it backwards.', 'start': 1612.646, 'duration': 0.961}, {'end': 1615.149, 'text': 'So we want to remove it.', 'start': 1613.967, 'duration': 1.182}], 'summary': 'Explains the rationale for iterating backwards through an array in order to delete elements without skipping or encountering issues.', 'duration': 27.489, 'max_score': 1587.66, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1587660.jpg'}, {'end': 1719.766, 'src': 'embed', 'start': 1664.626, 'weight': 3, 'content': [{'end': 1667.346, 'text': 'Now I need to figure out what are some nodes I need to check next.', 'start': 1664.626, 'duration': 2.72}, {'end': 1670.107, 'text': "It's anything that's neighboring that particular node.", 'start': 1667.727, 'duration': 2.38}, {'end': 1671.848, 'text': 'This one, this one, or this one.', 'start': 1670.407, 'duration': 1.441}, {'end': 1676.109, 'text': "As long as they aren't nodes we've already checked or finished with before.", 'start': 1671.988, 'duration': 4.121}, {'end': 1681.831, 'text': "Okay, so how do I get the neighbors? So I need some way, whoops, I'm in the wrong keyboard.", 'start': 1677.23, 'duration': 4.601}, {'end': 1688.013, 'text': 'I need some way of figuring out what are all of the neighbors of current.', 'start': 1682.791, 'duration': 5.222}, {'end': 1704.705, 'text': "Well guess what, I think a nice way of doing this One way of doing this would be to add a function in the let's add an array.", 'start': 1688.353, 'duration': 16.352}, {'end': 1707.808, 'text': "So let's have each spot keep track of its neighbors.", 'start': 1704.725, 'duration': 3.083}, {'end': 1710.991, 'text': "And let's add a function called add neighbors.", 'start': 1708.609, 'duration': 2.382}, {'end': 1719.766, 'text': "And what I'm going to do is do things like, OK, so add neighbors from a particular grid.", 'start': 1714.042, 'duration': 5.724}], 'summary': 'Identifying neighboring nodes and adding a function to track them in an array.', 'duration': 55.14, 'max_score': 1664.626, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1664626.jpg'}, {'end': 1767.544, 'src': 'heatmap', 'start': 1722.448, 'weight': 1, 'content': [{'end': 1729.393, 'text': "And so what I'm going to do is I'm going to say this.neighbors push grid.", 'start': 1722.448, 'duration': 6.945}, {'end': 1731.555, 'text': 'Oh boy, this is awkward.', 'start': 1730.494, 'duration': 1.061}, {'end': 1734.997, 'text': 'This.i plus 1.', 'start': 1731.595, 'duration': 3.402}, {'end': 1738.96, 'text': "I'm going to do something silly just to make it a little more readable.", 'start': 1734.997, 'duration': 3.963}, {'end': 1740.801, 'text': 'Say var i equals this.i.', 'start': 1739.64, 'duration': 1.161}, {'end': 1744.416, 'text': 'var j equals this dot j.', 'start': 1742.694, 'duration': 1.722}, {'end': 1746.217, 'text': 'I might need those out.', 'start': 1744.416, 'duration': 1.801}, {'end': 1748.92, 'text': "I'm losing my train of thought here, but this is fine.", 'start': 1747.098, 'duration': 1.822}, {'end': 1751.862, 'text': 'i plus one j.', 'start': 1750.021, 'duration': 1.841}, {'end': 1767.544, 'text': "So there's four neighbors, right? i plus one j, i minus one j, i j plus one, Ij minus 1 so these are the four neighbors.", 'start': 1751.862, 'duration': 15.682}], 'summary': 'The speaker discusses grid neighbors and variable assignments for i and j.', 'duration': 45.096, 'max_score': 1722.448, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1722448.jpg'}, {'end': 1945.921, 'src': 'embed', 'start': 1917.991, 'weight': 5, 'content': [{'end': 1920.973, 'text': 'Look at this comma in a totally nonsensical location.', 'start': 1917.991, 'duration': 2.982}, {'end': 1924.556, 'text': "That's not right at all.", 'start': 1923.135, 'duration': 1.421}, {'end': 1926.958, 'text': "A lot of you are screaming at the computer, I'm sure.", 'start': 1924.596, 'duration': 2.362}, {'end': 1930.936, 'text': 'Hopefully, you were just saying it in a nice way, like, excuse me.', 'start': 1928.035, 'duration': 2.901}, {'end': 1934.898, 'text': 'I might like to point out your small but subtle error there.', 'start': 1931.616, 'duration': 3.282}, {'end': 1937.018, 'text': "That's why debugging is good.", 'start': 1934.918, 'duration': 2.1}, {'end': 1938.799, 'text': "Let's look at this again.", 'start': 1937.979, 'duration': 0.82}, {'end': 1940.66, 'text': "Let's look at this.", 'start': 1939.259, 'duration': 1.401}, {'end': 1942.82, 'text': "And let's look at this spot.", 'start': 1941.26, 'duration': 1.56}, {'end': 1944.381, 'text': "And let's look at its neighbors.", 'start': 1943.201, 'duration': 1.18}, {'end': 1945.921, 'text': "It's got three neighbors.", 'start': 1944.621, 'duration': 1.3}], 'summary': 'Debugging helps identify errors in code, like the misplaced comma, with three neighbors.', 'duration': 27.93, 'max_score': 1917.991, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1917991.jpg'}], 'start': 1497.662, 'title': 'Javascript array manipulation and pathfinding algorithm', 'summary': 'Covers javascript array manipulation including triple equals, custom functions for adding and removing elements, and efficient backward looping. it also discusses pathfinding algorithm, neighbor evaluation, and potential issues with adding neighbors to a grid.', 'chapters': [{'end': 1610.063, 'start': 1497.662, 'title': 'Javascript array manipulation', 'summary': 'Provides insights into manipulating arrays in javascript, covering the use of triple equals, adding and removing elements from arrays using custom functions, and the advantage of looping through arrays backwards for efficient deletion. it also highlights the absence of a built-in function for arbitrary removal from arrays.', 'duration': 112.401, 'highlights': ['The chapter emphasizes the use of triple equals for testing in JavaScript, promoting accuracy and certainty in comparisons.', "It discusses the process of adding and removing elements from arrays, demonstrating the creation of a custom 'remove from array' function to address the absence of a built-in removal function in JavaScript.", 'The importance of looping through arrays backwards is explained, highlighting the advantage of this approach for efficient deletion of elements.']}, {'end': 1942.82, 'start': 1610.203, 'title': 'Pathfinding algorithm and neighbor evaluation', 'summary': 'Discusses pathfinding algorithm and neighbor evaluation, highlighting the process of adding neighbors to a grid and potential issues with the approach.', 'duration': 332.617, 'highlights': ['The algorithm focuses on evaluating nodes and determining the neighbors to be checked next. The process involves evaluating nodes, selecting the best node, and identifying neighboring nodes for further evaluation.', 'The speaker deliberates on the method of adding neighbors to a grid, emphasizing the need for a systematic approach. The discussion revolves around the systematic addition of neighbors to a grid, addressing the potential issues and considerations for each neighbor.', 'The speaker encounters a comma placement error, highlighting the importance of debugging in programming. An error in comma placement is highlighted, emphasizing the significance of thorough debugging in programming to rectify such issues.']}], 'duration': 445.158, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1497662.jpg', 'highlights': ['The chapter emphasizes the use of triple equals for testing in JavaScript, promoting accuracy and certainty in comparisons.', 'The importance of looping through arrays backwards is explained, highlighting the advantage of this approach for efficient deletion of elements.', "It discusses the process of adding and removing elements from arrays, demonstrating the creation of a custom 'remove from array' function to address the absence of a built-in removal function in JavaScript.", 'The algorithm focuses on evaluating nodes and determining the neighbors to be checked next. The process involves evaluating nodes, selecting the best node, and identifying neighboring nodes for further evaluation.', 'The speaker deliberates on the method of adding neighbors to a grid, emphasizing the need for a systematic approach. The discussion revolves around the systematic addition of neighbors to a grid, addressing the potential issues and considerations for each neighbor.', 'The speaker encounters a comma placement error, highlighting the importance of debugging in programming. An error in comma placement is highlighted, emphasizing the significance of thorough debugging in programming to rectify such issues.']}, {'end': 2911.95, 'segs': [{'end': 2146.163, 'src': 'embed', 'start': 2109.67, 'weight': 4, 'content': [{'end': 2123.934, 'text': 'So I want to say if closed set, so as long as the closed set does not include the neighbor, then I can change its g value right?', 'start': 2109.67, 'duration': 14.264}, {'end': 2125.895, 'text': 'Although, can I really?', 'start': 2124.995, 'duration': 0.9}, {'end': 2127.956, 'text': "So let's look at the algorithm here.", 'start': 2126.295, 'duration': 1.661}, {'end': 2130.69, 'text': 'Sorry, back here.', 'start': 2130.007, 'duration': 0.683}, {'end': 2139.599, 'text': "So you'll notice in the algorithm, that says the tentative G score.", 'start': 2131.132, 'duration': 8.467}, {'end': 2146.163, 'text': "The reason why I actually don't want to just automatically give it a new G score is I might have gotten to that.", 'start': 2140.079, 'duration': 6.084}], 'summary': 'Discussing the conditions for changing the g value in the algorithm.', 'duration': 36.493, 'max_score': 2109.67, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k2109670.jpg'}, {'end': 2578.844, 'src': 'embed', 'start': 2548.998, 'weight': 3, 'content': [{'end': 2556.424, 'text': "Because eventually, once I get to the end and it's done, I want to be able to trace back and find what that optimal path was.", 'start': 2548.998, 'duration': 7.426}, {'end': 2561.477, 'text': 'So what I need to do here is add oops, where am I?', 'start': 2557.932, 'duration': 3.545}, {'end': 2571.391, 'text': 'What I need to do in the code is I need to say sorry, I need to say neighbor.previous equals current.', 'start': 2561.497, 'duration': 9.894}, {'end': 2575.404, 'text': "So I want, I'm going to just use previous.", 'start': 2573.103, 'duration': 2.301}, {'end': 2578.844, 'text': "I could say came from or parent, but I'm going to say previous.", 'start': 2576.064, 'duration': 2.78}], 'summary': "The speaker aims to find the optimal path in the code and plans to use 'previous' for tracing back.", 'duration': 29.846, 'max_score': 2548.998, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k2548998.jpg'}, {'end': 2625.29, 'src': 'embed', 'start': 2602.605, 'weight': 0, 'content': [{'end': 2614.862, 'text': 'Wherever the open set is, Whenever the best, the item in the open set, the spot in the open set with the highest F score,', 'start': 2602.605, 'duration': 12.257}, {'end': 2619.706, 'text': 'the G score and the H score combined, the lowest, that is the best one.', 'start': 2614.862, 'duration': 4.844}, {'end': 2621.687, 'text': "if that happens to be the end, then I'm done.", 'start': 2619.706, 'duration': 1.981}, {'end': 2625.29, 'text': 'So now what I need to do is I need to find the path.', 'start': 2622.128, 'duration': 3.162}], 'summary': 'Algorithm finds best path using f, g, and h scores.', 'duration': 22.685, 'max_score': 2602.605, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k2602605.jpg'}, {'end': 2841.799, 'src': 'embed', 'start': 2816.945, 'weight': 1, 'content': [{'end': 2822.327, 'text': "Using the Euclidean distance, which is actually just kind of measuring that distance, isn't really accurate,", 'start': 2816.945, 'duration': 5.382}, {'end': 2825.528, 'text': "when I can only make steps that aren't diagonal, like this.", 'start': 2822.327, 'duration': 3.201}, {'end': 2830.411, 'text': "So there's actually a distance that's called a Manhattan distance or taxicab distance,", 'start': 2825.768, 'duration': 4.643}, {'end': 2833.573, 'text': 'which is just measuring the difference in x and the difference in y.', 'start': 2830.411, 'duration': 3.162}, {'end': 2839.317, 'text': 'So let me put that heuristic in, which I think will give us some results that look a bit more like what we might expect.', 'start': 2833.573, 'duration': 5.744}, {'end': 2841.799, 'text': "So I'm going to put that in.", 'start': 2840.738, 'duration': 1.061}], 'summary': 'Introducing manhattan distance heuristic for more accurate results.', 'duration': 24.854, 'max_score': 2816.945, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k2816945.jpg'}, {'end': 2911.95, 'src': 'embed', 'start': 2887.057, 'weight': 2, 'content': [{'end': 2887.717, 'text': 'the fourth row.', 'start': 2887.057, 'duration': 0.66}, {'end': 2892.054, 'text': "then actually what it's doing is it's optimally finding that path very quickly.", 'start': 2888.891, 'duration': 3.163}, {'end': 2896.117, 'text': "It doesn't have to check every possibility because what are we doing? We're using the A star algorithm.", 'start': 2892.074, 'duration': 4.043}, {'end': 2898.419, 'text': "So there's a couple of things that I want to add to this.", 'start': 2896.357, 'duration': 2.062}, {'end': 2901.041, 'text': "Number one, let's add some obstacles.", 'start': 2898.739, 'duration': 2.302}, {'end': 2904.904, 'text': 'So obstacles are really going to help us understand how this is working.', 'start': 2901.381, 'duration': 3.523}, {'end': 2911.95, 'text': "And number two, let's think about adding diagonals as well and how that works if we add diagonals.", 'start': 2905.344, 'duration': 6.606}], 'summary': 'A star algorithm finds optimal path quickly; adding obstacles and diagonals for testing.', 'duration': 24.893, 'max_score': 2887.057, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k2887057.jpg'}], 'start': 1943.201, 'title': 'Pathfinding algorithms', 'summary': 'Delves into evaluating neighbors, updating nodes, and optimizing the a* algorithm for pathfinding by exploring g scores, open sets, heuristics, and obstacle considerations.', 'chapters': [{'end': 2109.65, 'start': 1943.201, 'title': 'Pathfinding algorithm evaluation', 'summary': "Discusses evaluating neighbors in a pathfinding algorithm, iterating through each neighbor, calculating their 'g' value, and checking for their presence in the closed set before evaluation.", 'duration': 166.449, 'highlights': ["The first step in evaluating neighbors is to calculate their 'g' value, which represents the cost of reaching that neighbor from the starting point, with each step increasing 'g' by 1.", 'The algorithm checks for the presence of a neighbor in the closed set before evaluating it, aiming to avoid redundant evaluations of nodes that have already been visited through an optimal path.', "The process involves iterating through each neighbor, calculating their 'g' value, and adding them to the open set for evaluation before further processing."]}, {'end': 2602.303, 'start': 2109.67, 'title': 'A* algorithm: evaluating and updating nodes', 'summary': 'Discusses the a* algorithm, exploring the evaluation and updating of nodes based on g scores, open sets, heuristics, and neighbor relationships to optimize the pathfinding process.', 'duration': 492.633, 'highlights': ['The algorithm evaluates whether to change the G value of a closed set based on neighbor inclusion, open set presence, and efficient pathfinding, emphasizing the importance of checking if a neighbor is in the open set and if a better G score has been achieved (e.g., comparing temp g and neighbor.g).', 'The heuristic calculation using the raw Euclidean distance and the subsequent determination of the F-score by adding the G and H scores contribute to the overall node evaluation and path optimization process.', "The necessity of tracking 'came from' information by assigning the 'previous' node to each neighbor is highlighted, as it enables the determination of the optimal path by tracing back from the end node to the start node."]}, {'end': 2911.95, 'start': 2602.605, 'title': 'A* algorithm for pathfinding', 'summary': 'Explains the a* algorithm for pathfinding, highlighting the process of selecting the best path based on f score, g score, and h score, and optimizing the heuristic function for more accurate results. it also discusses the impact of obstacles and considerations for adding diagonal movements.', 'duration': 309.345, 'highlights': ['The A* algorithm selects the best path based on the spot in the open set with the highest combined F score, G score, and H score, ultimately finding the optimal path. The A* algorithm prioritizes the spot in the open set with the highest combined F score, G score, and H score, leading to the selection of the optimal path.', 'Optimizing the heuristic function with Manhattan distance instead of Euclidean distance yields more accurate pathfinding results, as demonstrated by the improved path selection. Replacing the Euclidean distance heuristic with the Manhattan distance improves pathfinding accuracy, resulting in more efficient path selection.', "The impact of obstacles on pathfinding is highlighted, emphasizing their role in understanding the algorithm's functionality. Incorporating obstacles provides insight into the algorithm's behavior and its ability to navigate around obstacles during pathfinding.", 'Considerations for adding diagonal movements to the algorithm are discussed, presenting potential implications and enhancements to the pathfinding process. The chapter explores the potential effects and improvements associated with incorporating diagonal movements into the A* algorithm for pathfinding.']}], 'duration': 968.749, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/aKYlikFAV4k/pics/aKYlikFAV4k1943201.jpg', 'highlights': ['The A* algorithm prioritizes the spot in the open set with the highest combined F score, G score, and H score, leading to the selection of the optimal path.', 'Replacing the Euclidean distance heuristic with the Manhattan distance improves pathfinding accuracy, resulting in more efficient path selection.', "Incorporating obstacles provides insight into the algorithm's behavior and its ability to navigate around obstacles during pathfinding.", "The necessity of tracking 'came from' information by assigning the 'previous' node to each neighbor is highlighted, as it enables the determination of the optimal path by tracing back from the end node to the start node.", 'The algorithm evaluates whether to change the G value of a closed set based on neighbor inclusion, open set presence, and efficient pathfinding, emphasizing the importance of checking if a neighbor is in the open set and if a better G score has been achieved (e.g., comparing temp g and neighbor.g).']}], 'highlights': ['The A* algorithm prioritizes the spot in the open set with the highest combined F score, G score, and H score, leading to the selection of the optimal path.', 'Replacing the Euclidean distance heuristic with the Manhattan distance improves pathfinding accuracy, resulting in more efficient path selection.', 'The presenter took 2.5 hours to resolve the bugs in implementing the A star pathfinding algorithm.', 'A-star algorithm uses heuristics to skip checking many possibilities, improving efficiency.', "The algorithm's potential application in pixel spaces is highlighted, with the mention of adding a steering agent to follow the path.", 'The importance of looping through arrays backwards is explained, highlighting the advantage of this approach for efficient deletion of elements.', 'The video demonstrates adding diagonal movement and obstacles to the optimal pathfinding algorithm.', 'The chapter emphasizes the use of triple equals for testing in JavaScript, promoting accuracy and certainty in comparisons.', "Incorporating obstacles provides insight into the algorithm's behavior and its ability to navigate around obstacles during pathfinding.", 'The process involves iterating through the open set to evaluate the nodes until the open set is empty, determining the completion of the algorithm.']}