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76 lines
1.6 KiB
76 lines
1.6 KiB
#include <iostream>
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#include <cstdio>
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#include <vector>
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#include <cstring>
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using namespace std;
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const int N = 2e5 + 10;
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int T, n, du[N];
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struct node {
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int to, w;
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};
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vector<node> c[N];
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bool v[N];
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int d[N], f[N];
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void clean() {
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memset(v, 0, sizeof v);
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memset(du, 0, sizeof du);
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memset(d, 0, sizeof d);
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memset(f, 0, sizeof f);
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for (int i = 1; i <= n; i++) c[i].clear();
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}
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void dp(int x) {
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v[x] = 1;
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int size = c[x].size() - 1;
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for (int i = 0; i <= size; i++) {
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int to = c[x][i].to, w = c[x][i].w;
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if (v[to]) continue;
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dp(to);
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if (du[to] == 1)
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d[x] += w;
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else
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d[x] += min(d[to], w);
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}
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return;
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}
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void dfs(int x) {
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v[x] = 1;
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int size = c[x].size() - 1;
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for (int i = 0; i <= size; i++) {
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int to = c[x][i].to, w = c[x][i].w;
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if (v[to]) continue;
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if (du[x] == 1)
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f[to] = d[to] + w;
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else
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f[to] = d[to] + min(f[x] - min(d[to], w), w);
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dfs(to);
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}
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return;
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}
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int main() {
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cin >> T;
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while (T--) {
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cin >> n;
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clean();
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int x, y, z;
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for (int i = 1; i < n; i++) {
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cin >> x >> y >> z;
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c[x].push_back((node){y, z});
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c[y].push_back((node){x, z});
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du[x]++;
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du[y]++;
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}
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dp(1);
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f[1] = d[1];
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memset(v, 0, sizeof v);
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dfs(1);
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int ans = 0;
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for (int i = 1; i <= n; i++) ans = max(ans, f[i]);
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printf("%d\n", ans);
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}
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return 0;
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} |