 # Question: Can BFS Be Used To Find Cycles?

## Does BFS work on weighted graphs?

BFS will not work on weighted graphs since the path with the fewest edges may not be the shortest if the edges it contains are expensive.

However, if all the weights are intergers and they are bounded by a small number, say k, we can still use BFS..

## Is self loop a cycle?

A self-loop or loop is an edge between a vertex and itself. An undirected graph without loops or multiple edges is known as a simple graph. … A cycle is a closed path, i.e. a path combined with the edge (vk,v1).

## Why BFS takes more memory than DFS?

For implementation, BFS uses a queue data structure, while DFS uses a stack. BFS uses a larger amount of memory because it expands all children of a vertex and keeps them in memory. It stores the pointers to a level’s child nodes while searching each level to remember where it should go when it reaches a leaf node.

## What is BFS algorithm example?

Breadth First Search (BFS) algorithm traverses a graph in a breadthward motion and uses a queue to remember to get the next vertex to start a search, when a dead end occurs in any iteration. As in the example given above, BFS algorithm traverses from A to B to E to F first then to C and G lastly to D.

## How do I check my cycle with BFS?

Steps involved in detecting cycle in a directed graph using BFS. Step-1: Compute in-degree (number of incoming edges) for each of the vertex present in the graph and initialize the count of visited nodes as 0. Step-3: Remove a vertex from the queue (Dequeue operation) and then. Increment count of visited nodes by 1.

## What are the applications of BFS?

Applications Of Breadth-First Search AlgorithmCrawlers in Search Engines: Breadth-First Search is one of the main algorithms used for indexing web pages. … GPS Navigation systems: … Find the Shortest Path & Minimum Spanning Tree for an unweighted graph: … Broadcasting: … Peer to Peer Networking:

## Which one is not an application of BFS?

Which of the following is not an application of Breadth First Search? Explanation: Breadth First Search can be applied to Bipartite a graph, to find the shortest path between two nodes, in GPS Navigation. In Path finding, Depth First Search is used. 7.

## How do you check if there is a cycle in an undirected graph?

To detect if there is any cycle in the undirected graph or not, we will use the DFS traversal for the given graph. For every visited vertex v, when we have found any adjacent vertex u, such that u is already visited, and u is not the parent of vertex v. Then one cycle is detected.

## What is undirected graph?

An undirected graph is graph, i.e., a set of objects (called vertices or nodes) that are connected together, where all the edges are bidirectional. An undirected graph is sometimes called an undirected network. In contrast, a graph where the edges point in a direction is called a directed graph.

## Can undirected graphs have self loops?

In particular, unless otherwise specified, a graph will refer to a simple undirected graph: an undirected graph where each edge connects two distinct vertices (thus no self-loops) and there is at most one edge between each pair of vertices (no parallel edges).

## What is the time complexity of BFS?

Time Complexity of BFS = O(V+E) where V is vertices and E is edges. Time Complexity of DFS is also O(V+E) where V is vertices and E is edges.

## Can topological sort detect cycles?

If the given graph contains a cycle, then there is at least one node which is a parent as well as a child so this will break Topological Order. Therefore, after the topological sort, check for every directed edge whether it follows the order or not.

## Where is BFS and DFS used?

BFS can be used to find the shortest path, with unit weight edges, from a node (origional source) to another. Whereas, DFS can be used to exhaust all the choices because of its nature of going in depth, like discovering the longest path between two nodes in an acyclic graph.

## What are the application of BFS and DFS?

We can detect cycles in a graph using DFS. If we get one back-edge during BFS, then there must be one cycle. Using DFS we can find path between two given vertices u and v. We can perform topological sorting is used to scheduling jobs from given dependencies among jobs.

## Is DFS faster than BFS?

Comparing BFS and DFS, the big advantage of DFS is that it has much lower memory requirements than BFS, because it’s not necessary to store all of the child pointers at each level. … Then, a BFS would usually be faster than a DFS. So, the advantages of either vary depending on the data and what you’re looking for.

## How does DFS detect cycle in undirected graph?

Approach: Run a DFS from every unvisited node. Depth First Traversal can be used to detect a cycle in a Graph. DFS for a connected graph produces a tree. There is a cycle in a graph only if there is a back edge present in the graph.

## Can we use BFS to detect cycle in an undirected graph in o v e time what about directed graphs?

Like directed graphs, we can use DFS to detect cycle in an undirected graph in O(V+E) time. … We do a BFS traversal of the given graph. For every visited vertex ‘v’, if there is an adjacent ‘u’ such that u is already visited and u is not parent of v, then there is a cycle in graph.

## Can BFS be used on directed graphs?

BFS and DFS in directed graphs For directed graphs, too, we can prove nice properties of the BFS and DFS tree that help to classify the edges of the graph. For BFS in directed graphs, each edge of the graph either connects two vertices at the same level, goes down exactly one level, or goes up any number of levels.

## What is a cycle graph theory?

In graph theory, a cycle in a graph is a non-empty trail in which the only repeated vertices are the first and last vertices. … A directed graph without directed cycles is called a directed acyclic graph. A connected graph without cycles is called a tree.