Submission #1169805

#	Time	Username	Problem	Language	Result	Execution time	Memory
1169805		CDuong	Airplane (NOI23_airplane)	C++20	100 / 100	166 ms	16640 KiB

Main

/*
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,fma,bmi,bmi2,sse4.2,popcnt,lzcnt")
*/

#include <bits/stdc++.h>
#define taskname ""
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define i64 long long
#define isz(x) (int)x.size()
using namespace std;

void solve() {
    int n, m;
    cin >> n >> m;

    vector<int> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }

    vector<vector<int>> g(n);
    for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        g[u].emplace_back(v);
        g[v].emplace_back(u);
    }

    const int inf = 1e9;
    vector<int> dis1(n, inf);
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    pq.emplace(0, 0); dis1[0] = 0;
    while (not pq.empty()) {
        auto [d, u] = pq.top();
        pq.pop();
        if (d != dis1[u]) continue;
        for (auto v : g[u]) {
            int nd = max(d + 1, a[v]);
            if (nd < dis1[v]) {
                dis1[v] = nd;
                pq.emplace(nd, v);
            }
        }
    }

    vector<int> disn(n, inf);
    pq.emplace(0, n - 1); disn[n - 1] = 0;
    while (not pq.empty()) {
        auto [d, u] = pq.top();
        pq.pop();
        if (d != disn[u]) continue;
        for (auto v : g[u]) {
            int nd = max(d + 1, a[v]);
            if (nd < disn[v]) {
                disn[v] = nd;
                pq.emplace(nd, v);
            }
        }
    }

    int res = inf;
    for (int i = 0; i < n; ++i) {
        res = min(res, max(dis1[i], disn[i]) * 2);
        for (auto u : g[i]) {
            res = min(res, max(dis1[i], disn[u]) * 2 + 1);
        }
    }
    cout << res << endl;
}

signed main() {

#ifndef CDuongg
    if (fopen(taskname".inp", "r"))
        assert(freopen(taskname".inp", "r", stdin)), assert(freopen(taskname".out", "w", stdout));
#else
    freopen("bai3.inp", "r", stdin);
    freopen("bai3.out", "w", stdout);
    auto start = chrono::high_resolution_clock::now();
#endif

    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int t = 1; //cin >> t;
    while(t--) solve();

#ifdef CDuongg
   auto end = chrono::high_resolution_clock::now();
   cout << "\n"; for(int i = 1; i <= 100; ++i) cout << '=';
   cout << "\nExecution time: " << chrono::duration_cast<chrono::milliseconds> (end - start).count() << "[ms]" << endl;
#endif

}

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