graph using queue c++

To create a graph using a queue in C++, you can follow these steps:

1. First, define a class to represent the graph. This class will contain a list of vertices and their connections.

2. Create a struct or class to represent a vertex. Each vertex should have a unique identifier and a list of adjacent vertices.

3. Implement a function to add a vertex to the graph. This function should take the vertex identifier as a parameter and add it to the list of vertices.

4. Implement a function to add an edge between two vertices. This function should take the identifiers of the two vertices and add each vertex to the other's list of adjacent vertices.

5. To implement the breadth-first search (BFS) algorithm using a queue, create a function that takes the starting vertex as a parameter.

6. Inside the BFS function, create a queue data structure and a boolean array to keep track of visited vertices.

7. Enqueue the starting vertex into the queue and mark it as visited.

8. While the queue is not empty, dequeue a vertex and process it.

9. For each adjacent vertex of the dequeued vertex, if it has not been visited, enqueue it into the queue and mark it as visited.

10. Repeat steps 8 and 9 until the queue is empty.

This algorithm will traverse the graph in a breadth-first manner, visiting all the vertices that are reachable from the starting vertex.