Submission #1197444

#	Time	Username	Problem	Language	Result	Execution time	Memory
1197444		caterpillow	Airplane (NOI23_airplane)	C++20	100 / 100	902 ms	37264 KiB

Main

#include <bits/stdc++.h>

using namespace std;

main() {
    cin.tie(0)->sync_with_stdio(0);
    
    int n, m; cin >> n >> m;
    if (n == 1) cout << "0\n", exit(0);
    vector<int> h(n);
    for (int &x : h) cin >> x;
    vector<vector<int>> adj(n);    
    for (int i = 0; i < m; i++) {
        int u, v; cin >> u >> v; u--, v--;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    using t3 = tuple<int, int, int>;
    auto funny_dijkstra = [&] (int s, vector<int> &dist, vector<int> &alt) {
        priority_queue<t3, vector<t3>, greater<>> pq;
        pq.push({h[s], h[s], s});
        while (pq.size()) {
            auto [d, a, u] = pq.top(); pq.pop();
            if (dist[u] < d) continue;
            dist[u] = d, alt[u] = a;
            for (int v : adj[u]) {
                int ndist = max(d + 1, h[v]);
                if (ndist < dist[v])
                    pq.push({ndist, max(alt[u], h[v]), v});
            }
        }
    };

    vector<int> dist0(n, 1e9), dist1(n, 1e9), alt0(n), alt1(n);
    funny_dijkstra(0, dist0, alt0);
    funny_dijkstra(n - 1, dist1, alt1);
    int ans = 1e9;
    for (int i = 0; i < n; i++) {
        if (alt0[i] == alt1[i] && h[i] == alt0[i])
            ans = min(ans, dist0[i] + dist1[i]);
    }
    cout << ans << '\n';
}

Compilation message (stderr)

Main.cpp:5:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    5 | main() {
      | ^~~~

• Subtask 1: 22 / 22
• Subtask 2: 10 / 10
• Subtask 3: 31 / 31
• Subtask 4: 37 / 37