PAT 1146 Topological Order

This is a problem given in the Graduate Entrance Exam in 2018: Which of the following is NOT a topological order obtained from the given directed graph? Now you are supposed to write a program to test each of the options.

Input Specification:

Each input file contains one test case. For each case, the first line gives two positive integers N (≤ 1,000), the number of vertices in the graph, and M (≤ 10,000), the number of directed edges. Then M lines follow, each gives the start and the end vertices of an edge. The vertices are numbered from 1 to N. After the graph, there is another positive integer K (≤ 100). Then K lines of query follow, each gives a permutation of all the vertices. All the numbers in a line are separated by a space.

Output Specification:

Print in a line all the indices of queries which correspond to "NOT a topological order". The indices start from zero. All the numbers are separated by a space, and there must no extra space at the beginning or the end of the line. It is graranteed that there is at least one answer.

Sample Input:

6 8
1 2
1 3
5 2
5 4
2 3
2 6
3 4
6 4
5
1 5 2 3 6 4
5 1 2 6 3 4
5 1 2 3 6 4
5 2 1 6 3 4
1 2 3 4 5 6

Sample Output:

3 4

#include<iostream>
#include<vector>
using namespace std;
int n, k, m;
vector<int> inDegree(1001, 0);
vector< int> Adj[1001], v(1001);
int main(){
  int i, j;
  cin>>n>>m;
  for(i=1; i<=m; i++){
    int v, u;
    cin>>v>>u;
    inDegree[u]++;
    Adj[v].push_back(u);
  }
  cin>>k;
  vector<int> ans;
  for(i=0; i<k; i++){
    for(j=0; j<n; j++) cin>>v[j];
    bool flag=true;
    vector<int> temp(1001, 0);
    for(j=0; j<n; j++){
      if(temp[v[j]]==inDegree[v[j]]){
        for(int idx=0; idx<Adj[v[j]].size(); idx++) temp[Adj[v[j]][idx]]++;
      }else{
        flag = false;
        break;
      }
    }
    if(!flag) ans.push_back(i);
  }
  cout<<ans[0];
  for(i=1; i<ans.size(); i++) cout<<" "<<ans[i];
  return 0;
}