Counting removing edges to make it forest of even nodes. (dfs applin)

https://www.hackerrank.com/challenges/even-tree

Even Tree (dfs application )

In this question we have to count what is the maximum number of forests (of even nodes)

 that can be made by removal of minimum edges.

Here child returns its parent the no. of nodes ,if the number of nodes(including parent itself ) is even

then ans=ans+1;

#include<bits/stdc++.h>

using namespace std;

int ans=0,visited[100000];

vector<int> v[100000];

int dfs(int nod)
{
    visited[nod]=1;


   int  total=1;                  ///self count

   if(v[nod].size()==1 && nod!=1)
    return 1;                /// the leaf child gives 1 to parent

  for(int i=0;i<v[nod].size();i++)
  {
     if(visited[v[nod][i]]==0)
      total+=dfs(v[nod][i]);
  }

  if(total%2==0)
        ans++;


  visited[nod]=0;

  return total;
}



int main()
{
 int n,e,i,j,k,a,b,l;
 cin>>n>>e;


 for(i=1;i<=e;i++)
 {
  cin>>a>>b;
  v[a].push_back(b);
  v[b].push_back(a);
 }

 int kk=dfs(1);

 cout<<ans-1<<endl;

return 0;
}

https://www.hackerrank.com/challenges/even-tree