拓扑排序

#include<iostream>
#include<vector>
#include<list>
#include<queue>
using namespace std;
class Graph
{
public:
    std::vector<list<int> > neighbour;
    std::vector<int> indegree;
	int verNum;
	int arcNum;
};
Graph makegraph()
{
	Graph g;
	cin>>g.verNum;
	cin>>g.arcNum;
	g.neighbour.resize(g.verNum+1);
	g.indegree.resize(g.arcNum+1);
	int v,m;
	for (int i = 0; i < g.arcNum; ++i)
	{
		/* code */
		cin>>v>>m;
		g.neighbour[v].push_back(m);//for list , add a elem, is push or push_back()?
		g.indegree[m]++;
	}
	return g;
}                                                                                                         
vector<int> topologicalSorting(Graph g)
{
  priority_queue <int, std::vector<int>, greater<int> >q;
  vector<int> ordering;
  for (int i = 1; i <= g.verNum; ++i)
  {
  	/* code */
  	if(g.indegree[i]==0)
  		q.push(i);
  }
  while(!q.empty())
  {
  	int v=q.top();
  	q.pop();
    ordering.push_back(v);
    list<int>::iterator it=g.neighbour[v].begin();
    while(it!=g.neighbour[v].end())
    {
    	g.indegree[*(it)]--;
    	if(g.indegree[*it]==0)
    		q.push(*it);
           it++;
           //priority_queue<int, std::vector<int, std::allocator<int> >, std::greater<int> >' has no member named 'push_back'
    }
  }
  return ordering;
}
int main()
{
	Graph graph=makegraph();
	std::vector<int> v=topologicalSorting(graph);
	for (int i = 0; i < v.size(); ++i)
	{
		/* code */
		cout<<v[i]<<"   ";
	}
	cout<<endl;
	system("pause");
	return 0;
}
/*
5 5 
3 4 
4 1 
3 2 
2 4 
5 3
*/