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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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 ...
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Breadth-first search on a tree in Python
The following code performs breadth first search on a mockup tree
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1answer
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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, ...
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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:
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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 ...
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414 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 ...
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1answer
79 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 ...
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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 ...
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93 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 ...
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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:
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1answer
134 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 ...
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473 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 ...
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1answer
195 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 ...
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653 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 ...
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3answers
403 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 ...
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2answers
225 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 ...
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Generalized Missionaries and Cannibals in Java - follow-up
See the previous and initial iteration.
Now I have incorporated all the points suggested by mdfst13, and have the following:
StateNode.java:
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1answer
555 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" -algorithm:
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4answers
434 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 ...
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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, ...
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Recursive Level Order traversal
I have come up with this code to do level order traversal recursively for a binary search tree.
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1answer
130 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.
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1answer
108 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 ...
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1answer
151 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 ...
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2answers
188 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 ...
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3answers
8k 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 ...
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1answer
15k 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?
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1answer
139 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 ...
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1answer
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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 ...
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1answer
444 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:
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1answer
820 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, ...
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2answers
446 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 ...
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2answers
422 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.
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3answers
245 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 ...
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1answer
144 views
Finding the node with the smallest maximum distance to all the other nodes
This code is supposed to find, in a graph, the node with the smallest maximum distance to all the other nodes. The problem from Quora is :
How do I find the node that has the least maximum ...
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4answers
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Python 8-Puzzle and solver
I wrote a simple 8-Puzzle and solver and am interested in seeing how it might be improved. Please let me know if any style or design changes might enhance the readability/performance of my code.
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1answer
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Graph Creation and BFS + DFS in C#
I was asked to implement a graph and BFS and DFS.
Please comment. Is it understandable? Is my algorithm correct? Are there any optimizations?
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3answers
440 views
Finding shortest paths in directed graphs
I have very little experience in programming with C++ and the following small "program" is the 2nd one I have ever written in that language. I am most interested in comments regarding naming ...
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2answers
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BFS shortest path program
The task was to find the shortest path between P and K in a maze. You can move horizontally and vertically, where # is a wall and ...
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1answer
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Breadth First Search not SOLID enough v2.0
Original question: Breadth First Search not SOLID enough
Here is my first attempt at refactoring. Instead of using a Tuple, I used a ...
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1answer
258 views
Optimizing breadth-first-search code
I wrote code using some kind of breadth-first-search algorithm in order to find a path (any path!) from a start point to an end point. There are no weights/different distances involved from path-to ...
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429 views
Breadth First Search not SOLID enough
The following code has a modified version of the Breadth First Search algorithm. It not only visits the nodes, but keeps track of the paths, so I can output various messages later. I would like to ...
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1answer
850 views
Crawl multiple pages at once
This an update to my last question.
I want to process multiple pages at once pulling URLs from tier_list in the crawl_web ...
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2answers
261 views
Basic search engine
I want to improve efficiency of this search engine. It works in about 10 seconds for a search depth of 1, but 4 minutes at 2 etc.
I tried to give straightforward comments and variable names, any ...
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2answers
685 views
BFS tree traversal Scala
I would love some feedback on the following code for BFS traversal in a binary tree. Is there a cleaner way to write this?
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Run time complexity of printing a binary tree level by level
I have some doubts about running time of following question. The problem is printing a binary tree level by level. For example if tree is like
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2answers
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Improving performance of A* search in PHP
I need to figure out what can be done to improve the performance of a A* search algorithm in PHP. The idea is to look for the shortest path, in number of hops, between two points in a "map". Actual ...
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Print binary search tree by levels function implementation
I do not like this implementation as is seems too much complicated. My idea was to implement some BFS algorithm variant.
Some points to notice:
I use one queue.
In the begining put the tree ...
10
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4answers
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Depth First Search & Breadth First Search implementation
I've implemented DFS and BFS implementations. I want to check if the code is readable, contains any issues, and can be improved.
GraphImplementation
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5
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1answer
112 views
BFS implementation that walks a tile-based field
I wrote a BFS implementation that walks a tile-based field. It takes a function that should return true for walkable tiles and false for walls. It also takes the start and end points. It currently ...
