Untitled

#include<stdio.h>

int q[20], front=-1,rear=-1,a[20][20], vis[20];

int delete();

void add(int item);

void bfs(int s,int n);

void main() {

	int n,e,i,s,j,u,v;

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

	printf("Enter the number of edges in the graph: "); 
	scanf("%d", &e);

	printf("Enter the edges (u, v):\n"); 
	for (i = 1; i<=e; i++)

	{

		scanf("%d %d", &u, &v);

		a[u][v] = 1;

	}

	printf("THE ADJACENCY MATRIX IS\n"); 
	for(i=1;i<=n;i++)
	{

		for(j=1;j<=n;j++)

		{

			printf("%d",a[i][j]);

		}

		printf("\n");

	}

	for(i=1;i<=n;i++)
		vis[i]=0;
	printf("ENTER THE SOURCE VERTEX :"); 
	scanf("%d",&s);

	bfs(s,n);

}

void bfs(int s,int n)

{

	int p,i;

	add(s);

	vis[s]=1;

	p=delete();

	if(p!=0) 
		printf("%d",p); 
	while(p!=0)

	{

		for(i=1;i<=n;i++) 
			if((a[p][i]!=0)&&(vis[i]==0)) { 
				add(i); 
				vis[i]=1; 
			}
		p=delete();

	

		if(p!=0)
			printf("%d ",p);
	}

	for(i=1;i<=n;i++) 
		if(vis[i]==0) 
			bfs(i,n);

}

void add(int item)

{

	if(rear==19) 
		printf("QUEUE FULL");
	else

	{

		if(rear==-1)

		{

			q[++rear]=item;

			front++;

		}

	else

		q[++rear]=item;

	}

}

int delete()

{

	int k;

	if((front>rear)||(front==-1))

		return(0);

	else

	{

		k=q[front++];

		return(k);

	}

}