Depth First Search : C program

consider the following graph and its adjacency matrix:









One of the DFS traversal of the graph is
0 1 2 3 4

Program :DFS
 
#include<stdio.h>

int a[20][20],q[20],visited[20],n;

void dfs(int v)
{
       int i;
       for (i=0;i<n;i++)                                // check all the vertices in the graph
       {
               if(a[v][i] != 0 && visited[i] == 0) // adjacent to v and not visited
              {
                       visited[i]=1;          // mark the vertex visited
                       printf("%d  ",i);
                       dfs(i);
              }
      }
}
int main()
{
    int v,i,j;
    printf("\n Enter the number of vertices:");
    scanf("%d",&n);
    for (i=0;i<n;i++)
    {
        visited[i]=0;
    }
    printf("\n Enter graph data in matrix form:\n");
    for (i=0;i<n;i++)
      for (j=0;j<n;j++)
       scanf("%d",&a[i][j]);
    printf("\n Enter the starting vertex:");
    scanf("%d",&v);
    printf("\n DFS traversal is:\n");
    visited[v]=1; // mark the starting vertex as visited
    printf("%d   ",v);
   
    dfs(v);
}

Output:

Output:

 Enter the number of vertices: 5

 Enter graph data in matrix form:
0 1 0 0 1
1 0 1 1 1
0 1 0 1 0
0 1 1 0 1
1 1 0 1 0

 Enter the starting vertex:0
 
DFS traversal is:
0   1  2  3  4