C++代码

一道朴实无华的拓扑排序题

#include<iostream>
#include<cstring>
using namespace std;
const int N = 110;
int e[N * 2], ne[N * 2], h[N], idx;
int d[N];
int q[N];
int n;

void add(int a, int b){ 
    e[idx] = b, ne[idx] = h[a], h[a] = idx++;
}

void topsort(){
    int tt = -1, hh = 0;
    for(int i = 1; i <= n; ++i)
        if(!d[i])
            q[++tt] = i;
    while(hh <= tt){
        int t = q[hh++];
        for(int i = h[t]; i != -1; i = ne[i]){
            int j = e[i];
            d[j]--;
            if(d[j] == 0) q[++tt] = j;
        }   
    }
    for(int i = 0; i < n; ++i) printf("%d ", q[i]);
}

int main(){
    cin >> n;
    memset(h, -1, sizeof h);
    int x;
    for(int i = 0; i < n; ++i)
        while(cin >> x, x) add(i + 1, x), d[x]++;
    topsort();
    return 0;
}