BFS

#include <stdio.h>

#define MAX 100

int graph[MAX][MAX];
int visited[MAX];
int queue[MAX];
int n;

void BFS(int start)
{
    int front = 0, rear = 0;

    visited[start] = 1;
    queue[rear++] = start;

    while (front < rear)
    {
        int vertex = queue[front++];
        printf("%d ", vertex);

        for (int i = 0; i < n; i++)
        {
            if (graph[vertex][i] == 1 && !visited[i])
            {
                visited[i] = 1;
                queue[rear++] = i;
            }
        }
    }
}

int main()
{
    int edges, u, v, start;

    printf("Enter number of vertices: ");
    scanf("%d", &n);

    printf("Enter number of edges: ");
    scanf("%d", &edges);

    printf("Enter edges (u v):\n");
    for (int i = 0; i < edges; i++)
    {
        scanf("%d %d", &u, &v);
        graph[u][v] = 1;
        graph[v][u] = 1;
    }

    printf("Enter starting vertex: ");
    scanf("%d", &start);

    BFS(start);

    return 0;
}