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35 lines
814 B
35 lines
814 B
2 years ago
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#include <bits/stdc++.h>
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using namespace std;
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const int N = 1e5 + 10, M = N << 1;
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int n, m;
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// 链式前向星
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int e[M], h[N], idx, w[M], ne[M];
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void add(int a, int b, int c = 0) {
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e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
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}
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int res[N];
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void dfs(int u, int val) {
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if (res[u]) return; // 如果已经标记过，不用重复标记
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res[u] = val; // 没有标记过，就标记一下
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for (int i = h[u]; ~i; i = ne[i]) {
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int j = e[i];
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if (!res[j]) dfs(j, val);
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}
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}
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int main() {
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memset(h, -1, sizeof h);
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cin >> n >> m;
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while (m--) {
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int a, b;
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cin >> a >> b;
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add(b, a);
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}
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for (int i = n; i >= 1; i--) dfs(i, i);
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for (int i = 1; i <= n; i++) cout << res[i] << ' ';
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return 0;
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}
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