dfs.c

#include <stdio.h>

#define size 9
int adj_mat[size][size];
int vis[size];
struct queue1
{
    int a[size];
    int front, rear;
} q1;
void enqueue(int x)
{
    if (q1.front == -1)
    {
        q1.front += 1;
        q1.rear += 1;
        q1.a[q1.front] = x;
        return;
    }
    q1.rear += 1;
    q1.a[q1.rear] = x;
    return;
}

int dequeue()
{
    int t;
    t = q1.a[q1.front];
    q1.front += 1;
    return t;
}

void bfs(int s)
{
    int p;
    enqueue(s);
    vis[s] = 1;
    p = dequeue();
    if (p != 0)
        printf("%d\t", p);

    while (p != 0)
    {
        for (int i = 0; i < size; i += 1)
        {
            if (adj_mat[p][i] == 1 && vis[i] == 0)
            {
                enqueue(i);
                vis[i] = 1;
            }
        }
        p = dequeue();
        if (p != 0)
            printf("%d\t", p);
    }
}

void main()
{
    int node, edges, sp, ep, sv;

    q1.front = -1;
    q1.rear = -1;

    printf("Hi.");
    for (int i = 0; i < size; i += 1)
    {
        for (int j = 0; j < size; j += 1)
        {
            adj_mat[i][j] = 0;
        }
    }
    for (int i = 1; i <= size; i++)
    {
        vis[i] = 0;
    }
    printf("\nHow many nodes : ");
    scanf("%d", &node);

    printf("\nhow many edges : ");
    scanf("%d", &edges);

    for (int i = 0; i < size; i += 1)
    {
        for (int j = 0; j < size; j += 1)
        {
            adj_mat[i][j] = 0;
        }
    }

    for (int i = 0; i < size; i += 1)
    {
        vis[i] = 0;
    }

    for (int i = 0; i < edges; i += 1)
    {
        printf("\nEnter the start point: ");
        scanf("%d", &sp);

        printf("\nEnter the end point: ");
        scanf("%d", &ep);

        adj_mat[sp][ep] = 1;
        adj_mat[ep][sp] = 1;
    }

    printf("\n Adjaceny Matrix");
    for (int i = 0; i < size; i += 1)
    {
        printf("\n");
        for (int j = 0; j < size; j += 1)
        {
            printf("%d\t", adj_mat[i][j]);
        }
    }

    printf("\nEnter the source vertex: ");
    scanf("%d", &sv);
    bfs(sv);
}