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.
180
questions
4
votes
1
answer
3k
views
BFS' shortest path unweighted directed graph
The code I have is based on BFS and a little bit of Dijkstra and returns the shortest path of an unweighted directed graph as an integer. I was wondering if someone could take a look at my code too ...
- 41
6
votes
1
answer
7k
views
Graph and Node classes with BFS and DFS functions
I've created a Node class and a Graph class
...
- 440
3
votes
2
answers
1k
views
CLRS Implementation of BFS and DFS in C++
I tried to implement BFS and DFS from Introduction to Algorithms by Cormen. Any suggestions on how to improve my code?
GraphStructures.h
...
- 85
4
votes
1
answer
1k
views
Implementation of BFS on a graph
I have written the code below as a BFS implementation. Could someone please review. In particular, I want to know if there could be a memory leak.
...
- 135
2
votes
1
answer
1k
views
Get a path between graph nodes using breadth-first search
This code is meant to implement a Graph class which has a method that returns a path between 2 nodes using breadth-first search.
I'm doing this to improve my style ...
- 435
0
votes
2
answers
189
views
Calculating shortest possible route between two given nodes
I recently came across this problem:
Heroes in Indian movies are capable of superhuman feats. For example,
they can jump between buildings, jump onto and from running trains,
catch bullets with ...
- 389
1
vote
0
answers
137
views
Efficient keyword trie implementation in C++ with failure/output links
For a current project implementing a parser for a bifurcation analysis tool, I wanted to utilize a keyword trie based solution, as there are possibly a ton of user supplied keywords. However, i found ...
- 4,221
1
vote
1
answer
1k
views
JavaScript breadth-first search algorithm
I have implemented a breadth-first search and I'm more or less looking for suggestions on how I can improve on what I've done here.
How to use:
...
- 397
1
vote
1
answer
12k
views
Print tree level by level including Empty node
Here is my code to print tree in a level by level way. It needs to print an empty node as well to keep tree structure like full binary tree for elegancy reasons.
I'm wondering if anything you think ...
- 3,443
3
votes
3
answers
6k
views
Create a complete binary tree and do level order traversal on it
How can I optimize this code?
...
26
votes
3
answers
55k
views
3
votes
0
answers
54
views
LinkedList of Nodes at each level - optimalization
That's already known problem: to return an array of linked lists that contain values of elements at each level. Eg for tree with depth n there should be n linked lists.
I wrote the solution:
...
- 131
3
votes
1
answer
829
views
Recursive Breadth First Search Knights Tour
This program was written on Windows 7 using Visual Studio 2012 Professional. Some of the issues encountered may have been fixed or changed in a more recent version.
This is a quote from my second ...
- 22.4k
2
votes
2
answers
346
views
Finding the Least Common Ancestor of a Binary Tree
Input a binary tree (the root node) and 2 other nodes that need to be assessed for finding the least common ancestor (LCA)
Code:
a. Finding the nodes first with either ...
- 511
5
votes
1
answer
300
views
Knights Tour - Improved Refactored Recursive Breadth First Search for
The development and testing was performed on a Dell M6400 Laptop (Intel Core 2 Duo) running Centos 7, g++ compiler version 4.8.5, compiler switches -O3 -std=c++0x -D__cplusplus=201103L. (machine ...
- 22.4k
2
votes
1
answer
68
views
ExtensionMethods for iterating hierarchically data structures depth/breath-first
I wrote a few simple extension methods that allow to traverse a hierachically data structure depth-first or breath-first using LINQ:
Usage:
...
- 8,528
8
votes
2
answers
9k
views
C++ Graph Class Implementation (adjacency list)
I've got a barebones C++ graph class implemented as an adjacency list. The graph consists of a vector of vertices. Each vertex has a vector of outgoing edges that store the destination vertex id. ...
- 145
4
votes
0
answers
2k
views
Breadth-first search: traditional and bidirectional in Python - follow-up
I have refactored the version of the previous (and initial) iteration according to the answer by alexwlchan. As a reminder, this snippet compares breadth-first search against its bidirectional variant....
- 26.7k
6
votes
1
answer
7k
views
Breadth-first search on a tree in Python
The following code performs breadth first search on a mockup tree
...
- 225
6
votes
1
answer
969
views
Recursive Breadth First Search for Knights Tour
This was written as an experiment in performance, based on another question here on CodeReview. Input into the algorithm is the number of squares on one edge of the chess board, the point of origin, ...
- 22.4k
3
votes
1
answer
194
views
Finding smallest number of moves
We are given a map of sides of length n and m (both n and m are less than 1000), divided into n*m fields (squares of side 1). The map looks (for example) like this:
...
user92977
9
votes
1
answer
1k
views
Graph theory using C++ STL
I'm trying to practice STL so I implemented breadth first search and depth first search. I have designed the graph class so that vertices can be arbitrary hashable object.
Any feedback would be ...
- 393
8
votes
2
answers
4k
views
C++ Graph Implementation
My data set is a list of Edges which are passed as a pair of integers. Based on that, I have the following graph implementation for BFS. Could someone please review ...
- 81
2
votes
1
answer
252
views
Graph radius in Java - follow-up
See the previous and initial iteration.
Terminology
Given an undirected graph \$G = (V, E)\$, the eccentricity of a node \$u \in V\$, \$e(u)\$, is the maximum length (number of edges) of a shortest ...
- 26.7k
6
votes
1
answer
3k
views
Breadth first search implementation (also includes functions for finding shortest path and number of connected components)
I've been practicing my algorithms using The Algorithm Design Manual. I've decided to implement the breadth first search section (5.7) using javascript. I also have a ...
- 445
0
votes
1
answer
915
views
Graph radius in Java
(See the next iteration.)
The following snippet is a brute-force algorithm for computing a graph radius in time \$\Theta(V^2 + VE)\$ and space \$\Theta(V)\$ simply by doing \$|V|\$ breadth-first ...
- 26.7k
1
vote
2
answers
5k
views
Breadth-first search: traditional and bidirectional in Python
(See the next iteration.)
I have this Python (3.4) script for demonstrating the performance of the BFS algorithm, both traditional and bidirectional:
...
- 26.7k
3
votes
1
answer
2k
views
BFS for modified shortest path
Given K descriptions for bus line paths that exists to lead students between N campuses. What is the minimum cost that a student will have to goes from campus 1 to campus N ?
The itinerary of each ...
- 597
3
votes
1
answer
6k
views
Breadth and Depth First Search in Ruby
I was tasked with building three individual methods; one to create a Binary Search Tree (BST), one to carry out a Breadth First Search (BFS), and one to carry out a Depth First Search (DFS).
Create ...
- 571
4
votes
1
answer
4k
views
Shortest path on a maze with keys and doors
The locks of the doors present in the maze are of 7 types: A, B, C, D, E, F and G. There are also some copies of keys around the maze, which can be of types a, b, c, d, e, f or g. A key of type a ...
- 597
5
votes
4
answers
5k
views
Path sum in binary tree
Root to leaf path sum equal to a given number
Given a binary tree and a number, return true if the tree has a root-to-leaf path such that adding up all the values along the path equals the given ...
- 449
5
votes
3
answers
642
views
SPOJ solution of GRAVITY
I am solving problem GRAVITY on SPOJ. Each test case is a rectangular ASCII grid of dimensions m × n, and you have to determine ...
- 51
2
votes
2
answers
2k
views
Breadth-First Search heuristics to find solution to Water Jug Challenge
I started learning AI recently. In AI, searches should be avoided and everything in AI is a search problem.
One of the easiest problem where we could use general AI search techniques is the water jug ...
- 283
5
votes
1
answer
7k
views
Generalized Missionaries and Cannibals in Java
See the next iteration.
I was in the mood for some basic AI, and decided to code up an algorithm for solving "\$M\$ missionaries, \$C\$ cannibals in the boat with \$B\$ places" -problem:
...
- 26.7k
1
vote
4
answers
2k
views
Checking whether a graph is bipartite using BFS
I am solving a simple problem that checks whether a graph is two-colourable (bipartite graph). I am using BFS for this approach using C++ STL. I've replaced cin and ...
4
votes
2
answers
736
views
Basic graph traversals
Below is an implementation of two graph traversals. Graph constructor creates a random graph with a fixed number of edges (fixed as a proportion of the maximum number of vertices, ...
- 593
4
votes
3
answers
8k
views
Recursive Level Order traversal
I have come up with this code to do level order traversal recursively for a binary search tree.
...
3
votes
1
answer
937
views
Doing tree search in Java
I have this tiny library for building unbalanced, binary trees and doing tree search on them. I tried hard to define a generic API that would allow custom implementations of trees.
...
- 26.7k
3
votes
1
answer
193
views
Yet another graph search
I noticed there were already countless implementations of graphsearch procedures on here, but there were a couple of features of my approach that I haven't seen in the others, plus I would greatly ...
- 295
1
vote
1
answer
607
views
Minesweeper algorithm that works within O(1) space complexity
For minesweeper algorithm, instead of the most obvious BFS or DFS solution, I want a O(1) space solution.
First of all, I'll explain how the program works. I will pass in a 2D array, with 1 ...
- 19
7
votes
2
answers
220
views
Search for Tree
Here is a search implementation for my tree. It searches each node in a breadth-first manner first, but it goes deeper in a depth-first manner, in the event it needs to go deeper. I know there may ...
user34073
6
votes
3
answers
33k
views
Shortest path using Breadth First Search
I have sample graphs like the following (un-directed un-weighted cyclic graphs). My goal is to find the shortest path between a given source and destination.
I have found this implementation on web ...
- 277
4
votes
1
answer
36k
views
Depth First Search and Breadth First Search in C++
I am trying to learn DFS and BFS. However, I just want to make sure that I am not doing anything wrong. Would you please determine if the BFS and DFS functions are correct?
...
- 391
3
votes
1
answer
691
views
Grid walk problem and solving it recursively
On CodeEval, there's a Grid Walk challenge:
There is a monkey which can walk around on a planar grid. The monkey can move one space at a time left, right, up or down. That is, from (x, y) the ...
- 445
6
votes
1
answer
41k
views
Printing a tree level by level
I have written a program to print a binary tree level by level on different lines, like the tree would actually look if drawn on paper.
I have done a BFS traversal and then I proceed to print the ...
- 333
3
votes
1
answer
4k
views
Sum of left and right nodes (individually) in a Binary Search Tree
I have written a program which calculates the sum of all the left nodes and the sum of right nodes in a Binary search tree.
I have used BFS to traverse the tree. The code is as follows:
...
- 333
5
votes
1
answer
4k
views
Shortest path through a maze
I was trying to solve this problem in Java:
Given a 2-D array of black and white entries representing a maze with designated entrance and exit points, find the shortest path from entrance to exit, ...
- 1,203
4
votes
2
answers
1k
views
BFS Maze Solver in Scala
I recently got a Scala developer position, so I'd like to get more comfortable with Scala on my own. Here is a maze solver that I wrote (previously in other languages) that I translated to Scala. Any ...
- 201
3
votes
2
answers
1k
views
Determining if there is a route between two nodes in a directed graph
This algorithm should return a boolean value, telling if there is a path between two nodes in a given directed graph.
...
- 131
7
votes
3
answers
352
views
Breadth-first search for clusters of pixels in a given color range
I am a beginner in programming languages, so I apologise if my code is badly formatted or doesn't make any sense.
My program gets an image and a RGB color range as input and it counts how many pixels ...
- 73