Submission #1188927

#	Time	Username	Problem	Language	Result	Execution time	Memory
1188927		caterpillow	Airplane (NOI23_airplane)	C++20	63 / 100	1097 ms	29504 KiB

Main

#include <bits/stdc++.h>

#pragma GCC optimise("O3,unroll-loops");

using namespace std;

int n, m, h[200005], dist0[200005], dist1[200005], alt0[200005], alt1[200005];
vector<int> adj[200005];

struct entry {
    int d, a, u;
    bool operator<(const entry &oth) const {
        return d > oth.d;
    }
};

void dijkstra(int s, int dist[], int alt[]) {
    priority_queue<entry> 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]) pq.push({max(d + 1, h[v]), max(alt[u], h[v]), v});
    }
}

main() {
    cin.tie(0)->sync_with_stdio(0);
    
    cin >> n >> m;
    if (n == 1) cout << "0\n", exit(0);
    for (int i = 0; i < n; i++) cin >> h[i];
    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);
    }

    memset(dist0, 0x3f, sizeof(dist0));
    dijkstra(0, dist0, alt0);
    memset(dist1, 0x3f, sizeof(dist1));
    dijkstra(n - 1, dist1, alt1);

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

Compilation message (stderr)

Main.cpp:29:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   29 | main() {
      | ^~~~

• Subtask 1: 22 / 22
• Subtask 2: 10 / 10
• Subtask 3: 31 / 31
• Subtask 4: 0 / 37