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54 lines
1.2 KiB
54 lines
1.2 KiB
#include <bits/stdc++.h>
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using namespace std;
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const int N = 100010;
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const int M = N << 1;
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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 n, m, timestamp, tot;
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int dfn[N], low[N], cut[N];
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void tarjan(int u, int fa) {
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dfn[u] = low[u] = ++timestamp;
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int son = 0;
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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 (!dfn[j]) {
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tarjan(j, fa);
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low[u] = min(low[u], low[j]);
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if (low[j] >= dfn[u] && u != fa) cut[u] = 1;
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if (u == fa) son++;
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}
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low[u] = min(low[u], dfn[j]);
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}
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//根节点单独讨论
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if (son >= 2 && u == fa) cut[u] = 1;
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}
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int main() {
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memset(dfn, 0, sizeof(dfn));
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memset(h, -1, sizeof(h));
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scanf("%d%d", &n, &m);
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while (m--) {
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int a, b;
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scanf("%d%d", &a, &b);
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add(a, b), add(b, a);
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}
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for (int i = 1; i <= n; i++)
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if (!dfn[i]) tarjan(i, i);
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for (int i = 1; i <= n; i++)
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if (cut[i]) tot++;
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printf("%d\n", tot);
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for (int i = 1; i <= n; i++)
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if (cut[i]) printf("%d ", i);
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return 0;
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} |