Submission #1128665

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128665		pemguimn	Airplane (NOI23_airplane)	C++17	100 / 100	399 ms	25708 KiB

Main

#include <bits/stdc++.h>
#define int long long
#define pii pair<int, int>
using namespace std;

const int N = 2e5 + 5, INF = 1e18 + 5;

int n, m, a[N];
vector<int> adj[N];

vector<int> go(int s){
    vector<int> d(n + 1, INF);
    d[s] = 0;
    priority_queue<pii> pq; pq.push({-d[s], s});
    while(!pq.empty()){
        pii cur = pq.top(); pq.pop();
        if(-cur.first != d[cur.second]) continue;
        int w = -cur.first, i = cur.second;
        for(int x : adj[i]){
            int nww = max(w + 1, a[x]);
            if(d[x] > nww){
                d[x] = nww; pq.push({-d[x], x});
            }
        }
    }
    return d;
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }
    for(int i = 1; i <= m; i++){
        int x, y; cin >> x >> y;
        adj[x].push_back(y), adj[y].push_back(x);
    }
    vector<int> d1 = go(1);
    vector<int> dn = go(n);
    int ans = INF;
    for(int i = 1; i <= n; i++){
        ans = min(ans, max(d1[i], dn[i]) * 2);
        for(int x : adj[i]){
            ans = min(ans, max(d1[i], dn[x]) * 2 + 1);
            ans = min(ans, max(d1[x], dn[i]) * 2 + 1);
        }
    }
    cout << ans << '\n';
    return 0;
}

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