43 lines
1.5 KiB
C++
43 lines
1.5 KiB
C++
// P1462 通往奥格瑞玛的道路。城市费二分，非负道路耗血用 Dijkstra。
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#include <bits/stdc++.h>
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using namespace std;
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using ll = long long;
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int main() {
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ios::sync_with_stdio(false); cin.tie(nullptr);
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int n, m; ll b; if (!(cin >> n >> m >> b)) return 0;
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vector<int> fee(n + 1), values;
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for (int i = 1; i <= n; ++i) { cin >> fee[i]; values.push_back(fee[i]); }
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vector<vector<pair<int,ll>>> g(n + 1);
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for (int i = 0, u, v; i < m; ++i) {
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ll w; cin >> u >> v >> w;
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g[u].push_back({v,w}); g[v].push_back({u,w});
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}
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auto check = [&](int X) {
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if (fee[1] > X || fee[n] > X) return false;
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const ll INF = 1LL << 60;
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vector<ll> dist(n + 1, INF);
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priority_queue<pair<ll,int>, vector<pair<ll,int>>, greater<pair<ll,int>>> pq;
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dist[1] = 0; pq.push({0,1});
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while (!pq.empty()) {
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auto [du,u] = pq.top(); pq.pop();
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if (du != dist[u]) continue;
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for (auto [v,w] : g[u]) {
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if (fee[v] > X) continue;
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if (du + w < dist[v]) {
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dist[v] = du + w; pq.push({dist[v],v});
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}
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}
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}
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return dist[n] <= b;
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};
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sort(values.begin(), values.end());
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values.erase(unique(values.begin(), values.end()), values.end());
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if (!check(values.back())) { cout << "AFK\n"; return 0; }
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int l = 0, r = (int)values.size() - 1;
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while (l < r) {
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int mid = l + (r-l)/2;
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if (check(values[mid])) r = mid; else l = mid + 1;
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}
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cout << values[l] << '\n';
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}
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