mirror of
https://gitcode.com/Zengtudor/alg2025.git
synced 2025-10-19 22:42:22 +00:00
100 lines
2.0 KiB
C++
100 lines
2.0 KiB
C++
#include <algorithm>
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#include <iostream>
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#include <queue>
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#include <vector>
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using ll = long long;
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const int MAXN = 2505;
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int n;
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int m;
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int k;
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ll sc[MAXN];
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std::vector<int> adj[MAXN];
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int dist[MAXN][MAXN];
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std::vector<int> pre[MAXN];
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void bfs(int s) {
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std::queue<std::pair<int, int>> q;
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q.push({s, 0});
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dist[s][s] = 0;
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while (!q.empty()) {
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auto [u, d] = q.front();
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q.pop();
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if (d > k) {
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continue;
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}
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for (int v : adj[u]) {
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if (dist[s][v] == -1) {
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dist[s][v] = d + 1;
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q.push({v, d + 1});
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}
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}
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}
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}
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int main() {
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std::ios_base::sync_with_stdio(false);
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std::cin.tie(nullptr);
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std::cin >> n >> m >> k;
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for (int i = 2; i <= n; ++i) {
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std::cin >> sc[i];
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}
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for (int i = 0; i < m; ++i) {
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int u, v;
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std::cin >> u >> v;
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adj[u].push_back(v);
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adj[v].push_back(u);
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}
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for (int i = 1; i <= n; ++i) {
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for (int j = 1; j <= n; ++j) {
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dist[i][j] = -1;
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}
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}
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for (int i = 1; i <= n; ++i) {
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bfs(i);
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}
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for (int i = 2; i <= n; ++i) {
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for (int j = 2; j <= n; ++j) {
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if (i == j)
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continue;
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if (dist[1][j] != -1 && dist[j][i] != -1) {
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pre[i].push_back(j);
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}
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}
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std::sort(pre[i].begin(), pre[i].end(), [&](int a, int b) { return sc[a] > sc[b]; });
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if (pre[i].size() > 3) {
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pre[i].resize(3);
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}
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}
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ll ans = 0;
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for (int b = 2; b <= n; ++b) {
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for (int c = 2; c <= n; ++c) {
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if (b == c)
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continue;
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if (dist[b][c] != -1) {
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for (int a : pre[b]) {
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for (int d : pre[c]) {
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if (a != c && a != d && b != d) {
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ans = std::max(ans, sc[a] + sc[b] + sc[c] + sc[d]);
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}
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}
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}
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}
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}
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}
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std::cout << ans << std::endl;
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}
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