Submission #1173724

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173724		somefolk	Airplane (NOI23_airplane)	C++20	100 / 100	220 ms	34032 KiB

Main

#include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <unordered_set>
#include <complex>
#include <list>
#include <cassert>
#include <chrono>
#include <random>
#include <stack>
#include <iomanip>
#include <fstream>
using namespace std;

#define endl "\n"
#define int long long

const int INF = 1e9+7;
const int MOD = 1e9+7;

int n, m;
vector<vector<pair<int, int>>> adj;

vector<int> dijkstra(int s){
    vector<int> dist(n+1, INF);
    vector<bool> vis(n+1, false);
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;

    dist[s] = 0;
    pq.push({0, s});

    while(!pq.empty()){
        int u = pq.top().second;
        pq.pop();

        if(vis[u]) continue;
        vis[u] = true;

        for(auto &i : adj[u]){
            int v = i.first, w = i.second;
            if(dist[v] > max(w, dist[u] + 1)){
                dist[v] = max(w, dist[u] + 1);
                pq.push({dist[v], v});
            }
        }
    }

    return dist;
}

void solve(){
    cin >> n >> m;
    vector<int> a(n+1);
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }

    adj.resize(n+1);
    for(int i = 0; i < m; i++){
        int u, v;
        cin >> u >> v;
        adj[u].push_back({v, a[v]});
        adj[v].push_back({u, a[u]});
    }

    vector<int> dist1 = dijkstra(1);
    vector<int> dist2 = dijkstra(n);

    int sol = INF;
    for(int i = 1; i <= n; i++){
        sol = min(sol, max(dist1[i], dist2[i])*2);
        for(auto &j : adj[i]){
            sol = min(sol, max(dist1[i], dist2[j.first])*2+1);
            sol = min(sol, max(dist1[j.first], dist2[i])*2+1);
        }
    }

    cout << sol << endl;
}

int32_t main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    int t = 1;
    // cin >> t;
    while(t--) solve();
    return 0;
}

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