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python/TangDou/AcWing/TopSort/1191_TopSort.cpp
HuangHai 1f397eca87 'commit'
2025-08-30 18:35:01 +08:00

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#include <bits/stdc++.h>
using namespace std;
const int N = 110, M = N * N;
int n;
int din[N];
// 链式前向星
int e[M], h[N], idx, w[M], ne[M];
void add(int a, int b, int c = 0) {
e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
}
vector<int> path;
// 求拓扑序的模板
/*
① 所有入度为0的点入队列
② 队头元素出队,遍历它相临的点,并且将相临的点入度-1
③ 如果减1后的入度为0,则此点入队列,意味着它的前序依赖已完成
*/
void topsort() {
queue<int> q;
// 所有入度为0的入队列
for (int i = 1; i <= n; i++)
if (din[i] == 0) q.push(i);
while (q.size()) {
int u = q.front();
q.pop();
path.push_back(u);
for (int i = h[u]; ~i; i = ne[i]) {
int v = e[i];
din[v]--;
if (din[v] == 0) q.push(v);
}
}
}
int main() {
memset(h, -1, sizeof h);
scanf("%d", &n);
for (int a = 1; a <= n; a++) {
int b;
while (scanf("%d", &b), b) { // b==0时结束读入
add(a, b);
din[b]++; // 入度++
}
}
// 拓扑序
topsort();
// 输出任意一组拓扑序
for (int i = 0; i < n; i++) printf("%d ", path[i]);
return 0;
}