C Program for DFS(Depth first search)

/*Program to perform depth first traversal on a graph */

#include <stdio.h>

int  v , adj[10][10] , visited[10] ;
/* Assuming maximum 9 vertices. */

void dfs(int k);

void main()
{
 int i,j;

 clrscr();

 /* Creating graph of v vertices */
 printf("Enter the number of vertices in the graph: ");
 scanf("%d",&v);

 for(i=1 ; i<=v ; i++)
   for(j=1 ; j<=v ; j++)
   {
     printf("Is vertex %d adjacent to vertex %d ? ",j,i);
     printf("Enter 1 if yes and 0 if no. ");
     scanf("%d",&adj[i][j]);
    }

 /* Making all the vertices as unvisited */
 for(i=1;i<=v;i++)
   visited[i]=0;

 printf("Depth first Search of the graph is as shown:\n");
 for(i=1;i<=v;i++)
   if(visited[i]==0)
     dfs(i);
     /* Initiating dfs from vertex i if it is not visited */

getch();
}

void dfs(int k)
{
  int j;
  visited[k]=1;           /* Visiting vertex k */
  printf("%d ",k);
  for(j=1; j<=v ; j++)
    if(adj[k][j] == 1)
      if(visited[j] ==0)
dfs(j);      /* Initiating dfs from vertex j */
}

/* The first if checks whether vertex j is adjacent to vertex k
     The second if checks whether j is visited or not */