DFS

#include<iostream>
using namespace std;
#include<stdlib.h>
#define ma 100
/////////////////////////////
struct vertex
{
    int d;
    struct vertex *next;
};
 int n;
  struct vertex *v[ma]={NULL};

  int visit[ma]={0};
///////////////////////////////
void value(int &a,int &b)
{
    cout<<"enter source and destination"<<endl;
    cin>>a>>b;
}
//////////////////////////////////
void create(struct vertex *v[],int n,int e)
{
    int i,j;
     int a,b;
    for(j=0;j<e;j++)
    {
        value(a,b);

        struct vertex *New=NULL,*ptr=NULL;
        New=new struct vertex;
        New->d=b;
        New->next=NULL;

        if(v[a]==NULL)
        {

            v[a]=New;
        }
        else
        {

            ptr=v[a];
            while(ptr->next!=NULL)
                ptr=ptr->next;
            ptr->next=New;
        }
    }
}
///////////////////////////////
void print(struct vertex *v[],int n,int e)
{
    int i;
    for(i=0;i<n;i++)
    {
        cout<<i<<"->";
        struct vertex *ptr=v[i];
        while(ptr!=NULL)
        {
            cout<<ptr->d<<" -> ";
            ptr=ptr->next;
        }
        cout<<endl;
    }
}
////////////////////////////
void dfs(int i)
{
    int j;
    struct vertex *p;
    cout<<i<<endl;
    p=v[i];
    visit[i]=1;
    while(p!=NULL)
    {
        j=p->d;
        if(visit[j]!=1)
        {

            dfs(j);
        }
        p=p->next;
    }
}
////////////////////////////////////
int main()
{
    int e;
    cout<<"enter number of edge"<<endl;
    cin>>e;
    cout<<"enter number of vertices"<<endl;
    cin>>n;

     create(v,n,e);
     print(v,n,e);
     cout<<"enter source vertex "<<endl;
     int s;
     cin>>s;
     cout<<"visited vertex are: "<<endl;
     dfs(s);
}