hiho一下 第四十八週（拓撲排序的應用）48

---

///////////////////////////////////////////////////////////////////////////////////////////////////////
作者：tt267
聲明：本文遵循以下協議自由轉載-非商用-非衍生-保持署名|Creative Commons BY-NC-ND 3.0
轉載請註明：http://blog.csdn.net/tt2767/article/details/46364717
///////////////////////////////////////////////////////////////////////////////////////////////////////

---

題目鏈接：http://hihocoder.com/problemset/problem/1175
隊列和棧都能過

#include<iostream>
#include<algorithm>
#include <iterator>
#include<cmath>
#include<vector>
#include<stack>
#include<map>
#include<set>
#include<staue>
#include<functional>
#include<stdlib.h>
#include<cstring>
using namespace std;
#define PI acos(-1.0)
#define MOD 142857
vector<int> Graph[500009];
stack<int> sta;
int N,M,K,ver;
int u,v;
int deg[500009] = {0};
int vir[500009] = {0};
int solve();

int main()
{
    memset(vir,0,sizeof(vir));
    memset(deg,0,sizeof(deg));
    scanf("%d%d%d",&N,&M,&K);
    for(int i = 0 ; i < K ; i++)
    {
        scanf("%d",&ver);
        vir[ver]++;
    }
    for(int i = 0; i < M ; i++ )
    {
        scanf("%d%d",&u,&v);
        Graph[u].push_back(v);
        deg[v]++;
    }

    printf("%d\n",solve());

    return 0;
}

int solve()
{
    int x,Count = 0;
    for(int i = 0 ; i < N ; i++ )
        if(deg[i] == 0)
            sta.push(i);

    while(!sta.empty())
    {
        x = sta.top();
        sta.pop();
        Count += vir[x];
        Count %= MOD;
        for(vector<int>::iterator it = Graph[x].begin() ; it != Graph[x].end() ; it++)
        {
            if( !deg[*it] )
                continue;
            deg[*it]--;
            vir[*it] += vir[x];
            vir[*it] %= MOD;
            if( !deg[*it] )
                sta.push(*it);
        }
    }

    return Count;
}