Questions tagged [breadth-first-search]

In graph theory, breadth-first search (BFS) is a graph search algorithm that begins at the root node and explores all the neighboring nodes. Then for each of those nearest nodes, it explores their unexplored neighbor nodes, and so on, until it finds the goal.

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31 views

Breadth First Search Block Puzzle

I am creating a program that will be given a text file as output with the board's dimension and the piece id along with the piece width and length. The goal is to arrange all blocks in the board ...
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Python PacMan with son

I have been coding 'Pac-Man' with my 16yo. A hopefully not too boring project to help improve his Python coding. We have just moved the 'Ghosts' into a class which was a good first introduction to ...
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Prepare Bunnies Escape

The problem You have maps of parts of the space station, each starting at a prison exit and ending at the door to an escape pod. The map is represented as a matrix of ...
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21 views

Breadth first search of a binary-tree with channels

As an exercise in using channels in Go I implemented a breadth-first traversal of a binary tree, using a channel as a queue to store the order of the nodes to traverse. After ironing out a bunch of ...
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01 Matrix is too slow when solved using DFS

I tried solving Leetcode 01 Matrix problem. It is running too slow when solved using DFS approach. Given a matrix consists of 0 and 1, find the distance of the nearest 0 for each cell. The distance ...
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1answer
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K-clustering algorithm using Kruskal MST with Disjoint Set in place to check for cycles

here below a working implementation that finds the minimal distance between k(set =4 below) clusters in a graph. I have doubts mainly on the implementation of the ...
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159 views

Generating unique 2D numpy arrays with 2 adjacent row elements swapped while using BFS in Python

So I have a 12 x 6 2D numpy array for input which consists of 7 possible board objects (characters from 'abcdefg'). From a 2D numpy array I wish to generate all the possible unique 2D arrays, in whose ...
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Breadth First Search Python Implementation

I have the below implementation of the BFS algorithm, in which I've used OrderedDict instead of a list or ...
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Routes Between Node, Cracking the coding interview

I am going though Cracking the coding interview and trying to improve my coding interview skills. The question is "Given a directed graph, design an algorithm to find out whether there is a route ...
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1answer
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Depth First Search vs Breadth First Search

So after years of teaching myself, I think I'm ready to stand on the shoulders of giants and ask you a good question! I have a tree of nodes. What I want is a function that returns an array of the ...
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Parsing a Graph To Convert It Into Adjacency Lists And CSR And Then Make Connection Queries Using Bidirectional BFS

I was assigned an university project where I had to parse directed graph files coming from SNAP and then convert them into CSR (Compressed Sparse Row) format. Then the client must have the ability to ...
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Minimum router Peripherality Breadth First Search (BFS) Algorithm performance

I have solved the MinRouterPeripherality task in codility using javascript using Breadth First Search(BFS) approach. However time complexity is O(N^2). I am really ...
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Is this breadth-first search correct?

I wrote a program that is supposed to be a breadth-first search algorithm, but I'm very new to search algorithm so I don't know if my method is very effective or if there is a simpler way to do this. ...
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111 views

Finding shortest path in matrix

Given an N x N matrix of positive integers, I need to find the shortest path from the first cell of matrix to the last cell of matrix. I can move exactly x steps from any cell, where x is the value of ...
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Breadth-first search(BFS) Implementation in Python 3 [closed]

I have implemented a BFS. Does this look like a proper implementation of BFS in Python 3? And if you think something needs to be improved, say it. ...
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1answer
559 views

LeetCode: Rotting Oranges in C#

https://leetcode.com/problems/rotting-oranges/ Please review for coding style in 40 minutes job interview. In a given grid, each cell can have one of three values: the value 0 representing an ...
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752 views

Maze image solver and animator in Python

This maze solver is a continuation to the maze generator I posted here recently Maze generator & animator in Python This code takes an image containing a 2-color maze as input and solves the maze ...
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2answers
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Determine if a string is a sequence of dictionary words

This is Leetcode problem 139: "Wordbreak" Problem: Given a non-empty string s and a dictionary wordDict containing a list ...
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Typesetting bidirectional breadth first search with Algotype.js

So I have this: And the typesetting code is here: ...
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1answer
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Javascript Tree Class 2

This question is the second version of the code here. I'm writing a general tree class. Specifically, each node should have oen parent, some number of children, and hold a value. I'm looking for ...
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543 views

Javascript Tree Class

I got caught in the trap of implementing my own data structure. I've created a very general tree structure, where each node gets one parent, some children, and holds a value. I'm mostly looking for ...
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1answer
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Optimising the BFS

The input graph to the bfs function is in the form of edge list representation. ...
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1answer
332 views

(Leetcode) Snakes and Ladders

This is a Leetcode problem - On an \$N\$ x \$N\$ board, the numbers from 1 to N * N are ...
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2answers
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(Leetcode) Escape a large maze

This is a Leetcode problem - In a 1 million by 1 million grid, the coordinates of each grid square are (x, y) with \$0\$ \$<=\$ ...
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1answer
195 views

(Leetcode) K-similar strings in Python

This is a Leetcode problem - Strings A and B are K-similar (for some non-negative integer ...
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1answer
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(Leetcode) Sliding puzzle in Python

This is a Leetcode problem: On a 2 x 3 board, there are 5 tiles represented by the integers 1 through ...
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1answer
106 views

Leetcode: Find-bottom-left-tree-value

https://leetcode.com/problems/find-bottom-left-tree-value/ Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Input: ...
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1answer
114 views

LeetCode: Employee-importance BFS

You are given a data structure of employee information, which includes the employee's unique id, his importance value and his direct subordinates' id. For example, employee 1 is the leader of ...
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1answer
221 views

Rubik's Cube in Java

I have this Java implementation of a Rubik's cube's state. My primary concern is DRYness of my code: RubiksCubeNode.java ...
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Breadth-first search in Java: Competitive style - follow-up

I have improved my BFS in Java according to vnp's suggestions. Again, we wish to find shortest paths in directed unweighted graphs using BFS, competitive style (no ...
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274 views

LeetCode: N-ary Tree Level Order Traversal

https://leetcode.com/problems/n-ary-tree-level-order-traversal/ Given an n-ary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example, ...
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3answers
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LeetCode: maximum-depth-of-n-ary-tree

https://leetcode.com/problems/maximum-depth-of-n-ary-tree/ Given a n-ary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the ...
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295 views

Breadth-first search in Java: competitive style

Here my attempt was to write a graph algorithm the way a competitive programmer would write under time pressure. The problem to solve was to find a shortest path in a directed, unweighted graph using ...
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1answer
238 views

Object-Oriented Breadth-First Search Implementation

My goal is to write a GUI application where a user can create a maze and select an algorithm. The passage of the algorithm from a selected start and end point should be visualized. The following ...
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Find the shortest path between two points in a 2D matrix with obstacles

I need to find shortest path between two points in a grid given an obstacles.. Given a 2 dimensional matrix where some of the elements are filled with 1 and rest of the elements are filled. Here ...
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1answer
60 views

Find the longest connect cells region per color

I have been studying graphs/BFS/DFS. working on wrapping my head around the following problem Given a grid [m,n] where each cell has a value denotes a color, find the longest connected region that ...
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Java breadth-first search for finding the shortest path on a 2D grid with obstacles

Please review my Breadth-first search algorithm implementation in Java for finding the shortest path on a 2D grid map with obstacles. The findPath() method ...
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1answer
580 views

Maze solver BFS in Haskell

I am really excited that I just wrote my Haskell maze solution in bfs. This is my very first haskell (and I still haven't tried to build a maze in haskell so that maze is hard coded xD) ANY ...
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1answer
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Pramp: Sales path

the question is taken from Pramp(really cool site!) there is a more straight forward solution. using recursion. but I thought trying it using BFS. please review only the code of GetCheapestCost ...
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1answer
154 views

BFS Pathfinding algorithm using Javascript generator

I'm implementing a BFS traversal in a grid-like structure. Because I wanted to experiment with ES6 Generators for a long time, I thought I'd implement the search using that abstraction. I am sure ...
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1answer
187 views

Flood Fill using unordered_map which has user-defined type as key

I have an implementation of the flood fill algorithm. Assume that an image is provided as a vector of ...
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3answers
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Find maximum area of island in matrix

I recently solved the problem below from leetcode: Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical)....
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Iterator for BFS binary tree traversal

I implemented an iterator pattern for C# using IEnumerator and IEnumerable. The goal of the implementation is to traverse a ...
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1answer
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Solve 8-tile sliding puzzle

I created a BFS algorithm in order to solve an 8-puzzle, and while it works, it is awfully slow compared to my DFS implementation. My main point of concern is the puzzleExists() function, which ...
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1answer
1k views

Print BFS implementation in JavaScript

Given a graph and a starting vertex print the value of each vertex in a breadth first order. Let's code out a general BFS algorithm printing each vertex's value in a BFS order. We are given a graph ...
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1answer
10k views

Searching a maze using DFS and BFS in Python 3

I solved the problem posted from Make School Trees and Maze article, which asks me to searching a maze using DFS and BFS in Python. Here's the final output from PyGame: I would like to ask for code ...
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2answers
9k views

Breadth First Search implementation in Python 3 to find path between two given nodes

This is my Breadth First Search implementation in Python 3 that assumes cycles and finds and prints path from start to goal. Some background - Recently I've been preparing for interviews and am ...
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1answer
461 views

Bidirectional BFS on a matrix in Python 2.7

This code is a bidirectional BFS search. Given any two points in a matrix having 0's and 1's, I would like to find if there exists a path between them. Also note that it is forbidden to enter a cell ...
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1answer
9k views

Perform BFS on a Binary Tree

Task: Perform Breadth first traversal on a Binary Search Tree and print the elements traversed. ...
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3k views

Breadth First Search using adjacency list

I want to improve this code using STL. Let me know if I should add any other function in this code. ...