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59 lines
1.1 KiB
59 lines
1.1 KiB
#include <bits/stdc++.h>
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using namespace std;
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const int N = 200010, M = N << 1;
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#define int long long
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#define endl "\n"
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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;
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int sz[N];
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int f[N];
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void dfs(int u, int fa) {
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sz[u] = 1;
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for (int i = h[u]; ~i; i = ne[i]) {
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int v = e[i];
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if (v != fa) {
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dfs(v, u);
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sz[u] += sz[v];
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}
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}
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}
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void dp(int u, int fa) {
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for (int i = h[u]; ~i; i = ne[i]) {
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int v = e[i];
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if (v != fa) {
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f[v] = f[u] + sz[1] - 2 * sz[v];
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dp(v, u);
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}
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}
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}
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signed main() {
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// 初始化链式前向星
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memset(h, -1, sizeof h);
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cin >> n;
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for (int i = 1; i < n; i++) {
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int a, b;
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cin >> a >> b;
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add(a, b), add(b, a);
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}
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dfs(1, 0);
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for (int i = 1; i <= n; i++) f[1] += sz[i];
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dp(1, 0);
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int ans = -0x3f;
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for (int i = 1; i <= n; i++) ans = max(ans, f[i]);
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cout << ans << endl;
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}
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