POJ 1285 确定比赛名词 （拓扑排序）

#include
using namespace std;
const int maxn = 1e5 + 5;

struct node
{
    int to, next;
}e[maxn << 1];
int head[maxn], in[maxn], n, m, cnt;
void init() {
    memset(head, -1, sizeof(head));
    memset(in, 0, sizeof(in));
    memset(e, 0, sizeof(e));
    cnt = 0;
}
void add (int from, int to) {
    e[++cnt].to = to;
    e[cnt].next = head[from];
    head[from] = cnt;
}
void topsort() {
    priority_queue , greater  > q;
    vector  ans;
    for (int i = 1; i <= n; i++) {
        if (!in[i]) q.push(i);
    }
    while (!q.empty()) {
        int u = q.top();
        q.pop();
        ans.push_back(u);
        for (int i = head[u]; i != -1; i = e[i].next) {
            int v = e[i].to;
            in[v]--;
            if (!in[v]) q.push(v);
        }
    }
    for (int i = 0; i < ans.size() - 1; i++) cout << ans[i] << " ";
    cout << ans[ans.size() - 1] << endl;
}

int main()
{
    while (cin >> n >> m) {
        init();
        for (int i = 0; i < m; i++) {
            int ui, vi;
            cin >> ui >> vi;
            add (ui, vi);
            in[vi]++;
        }
        topsort();
    }
    return 0;
}

 

拓扑排序模板题，注意多样例输出 和最后一个输出后面没有空格