mirror of
https://git.sb/baoshuo/OI-codes.git
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68 lines
1.2 KiB
C++
68 lines
1.2 KiB
C++
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#include <iostream>
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#include <algorithm>
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#include <functional>
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#include <limits>
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#include <utility>
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#include <vector>
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using std::cin;
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using std::cout;
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const char endl = '\n';
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const int N = 3e5 + 5;
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int n, d[N];
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long long f[N][2];
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std::vector<std::pair<int, int>> g[N];
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void dfs(int u, int fa) {
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std::vector<long long> weights;
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for (auto e : g[u]) {
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int v = e.first,
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w = e.second;
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if (v == fa) continue;
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dfs(v, u);
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weights.push_back(f[v][0] + w - f[v][1]);
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f[u][0] += f[v][1];
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f[u][1] += f[v][1];
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}
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std::sort(weights.begin(), weights.end(), std::greater<>());
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for (int i = 0; i < weights.size(); i++) {
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if (weights[i] <= 0) break;
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if (i < d[u] - 1) f[u][0] += weights[i];
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if (i < d[u]) f[u][1] += weights[i];
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}
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if (!d[u]) f[u][0] = std::numeric_limits<int>::min();
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}
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int main() {
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std::ios::sync_with_stdio(false);
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cin.tie(nullptr);
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cin >> n;
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for (int i = 1; i <= n; i++) {
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cin >> d[i];
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}
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for (int i = 1, u, v, w; i < n; i++) {
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cin >> u >> v >> w;
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g[u].emplace_back(v, w);
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g[v].emplace_back(u, w);
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}
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dfs(1, 0);
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cout << f[1][1] << endl;
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return 0;
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}
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