9. Print all the nodes reachable from a given starting node in a digraph using BFS method

#include<stdio.h>
#include<conio.h>
void distance(int,int);
int a[10][10];
void main()
{
int i,j,n;
clrscr();
printf("\n enter the number of vertices in the diagraph:");
scanf("%d",&n);
printf("\n enter the adjacency matrix\n");
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
scanf("%d",&a[i][j]);
for(i=1;i<=n;i++)
{
printf("\n the starting vertex is %d\n",i);
distance(i,n);
printf("\n\t press enter for other source vertex\n");
getch();
}
}
void distance(int v,int n)
{
int queue[40],visited[20],dis[20],front,rear,i,j;
for(i=1;i<=n;i++)
visited[i]=dis[i]=0;
front=rear=0;
queue[rear++]=v;
visited[v]=1;
do
{
i=queue[front++];
for(j=1;j<=n;j++)
if(a[i][j]&&!visited[j])
{
dis[j]=dis[i]+1;
queue[rear++]=j;
visited[j]=1;
printf("\n\t the vertex %d to %d is of distance=%d\n",v,j,dis[j]);
}
}
while(front<rear);
}