Topological sort

// Note: topological sort result is not unique . so don't worried

#include <iostream>
#include <vector>
#include <iterator>
#include <queue>
using namespace std;


void topologicalsort(vector<int>v[],int n)
{
    vector<int>indegree(n,0);
    vector<int>::iterator it;

    for(int i=0; i<n; i++)
    {
        for(it=v[i].begin(); it !=v[i].end(); it++)
        {
            indegree[*it]++;
        }
    }


    queue<int>q;
    vector<int>result;

    for(int i=0; i<n; i++)
    {
        if(indegree[i]==0)
            q.push(i);
    }
    int c=0;
    while(!q.empty())
    {
        int m=q.front();
        result.push_back(m);
        q.pop();

        for(it=v[m].begin(); it !=v[m].end(); it++)
        {
            --indegree[*it];

            if(indegree[*it]==0)
            {
                q.push(*it);
            }
            c++;

        }


    }
    if(c==n)
    {
        cout<< "Top sort: ";

        for(int i=0; i<result.size(); i++)
            cout<<result[i]<< " ";
        cout<<endl;
    }
    else
    {
      cout<< "The graph is not a DAG"<<endl;
      return ;
    }



}

int main()
{

    int node,edge;

    cout<< "Number of the nodes and edges: ";
    cin>>node>>edge;
    vector<int>v[node];

    cout<< "Enter edge information(u,v)"<<endl;
    for(int i=0; i<edge; i++)
    {
        int m,n;
        cin>>m>>n;
        v[m].push_back(n);
    }
    topologicalsort(v,node);

    return 0;
}

/*
4 4
0 1
2 0
2 1
2 3

4 4
0 1
1 2
2 1
2 3

*/