Depth_First_Search.cpp

//DEPTH FIRST SEARCH
#include<stdio.h>
#include<conio.h>
int a[20][20],reach[20],n;
void dfs(int v)
{
     int i;
     reach[v]=1;
     for(i=1;i<=n;i++)
     if(a[v][i] && !reach[i])
     {
                printf("\n %d->%d",v,i);
                dfs(i);
     }
}
int main()
{
    int i,j,count=0;
    printf("Enter the no. of vertices: ");
    scanf("%d",&n);
    for(i=1;i<=n;i++)
    {
                     reach[i]=0;
                     for(j=1;j<=n;j++)
                     a[i][j]=0;
    }
    printf("\nEnter the adjacency matrix: ");
    for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
    {
                    scanf("%d",&a[i][j]);
    }
    dfs(1);
    printf("\n");
    for(i=1;i<=n;i++)
    {
                     if(reach[i])
                     count++;
    }
    if(count==n)
    printf("Graph is connected");
    else
    printf("Graph is not connected");
    getch();
    return 0;
}