Submission #1326570

#	Time	Username	Problem	Language	Result	Execution time	Memory
1326570		Bolatulu	Airplane (NOI23_airplane)	C++20	100 / 100	275 ms	30836 KiB

Main

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define all(x) (x).begin(), (x).end()
#define md ((tl + tr) >> 1)
#define TL v + v, tl, md
#define TR v + v + 1, md + 1, tr
#define F first
#define S second
#define pii pair<int, int>
#define int ll

const int maxn = 1e6 + 7;
const ll inf = 1e18 + 7;

int n, m, a[maxn], d[2][maxn];
vector<int> g[maxn];
pii e[maxn];

void solve() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i <= m; i++) {
        cin >> e[i].F >> e[i].S;
        g[e[i].F].push_back(e[i].S);
        g[e[i].S].push_back(e[i].F);
    }
    fill(d[0] + 1, d[0] + n + 1, inf);
    fill(d[1] + 1, d[1] + n + 1, inf);

    priority_queue<pii, vector<pii>, greater<pii>> q;
    d[0][1] = 0;
    q.push({0, 1});

    while (!q.empty()) {
        auto [D, v] = q.top();
        q.pop();

        if (D != d[0][v]) continue;

        for (auto to : g[v]) {
            if (max(d[0][v] + 1, a[to]) < d[0][to]) {
                d[0][to] = max(d[0][v] + 1, a[to]);
                q.push({d[0][to], to});
            }
        }
    }

    d[1][n] = 0;
    q.push({0, n});
    
    while (!q.empty()) {
        auto [D, v] = q.top();
        q.pop();

        if (D != d[1][v]) continue;

        for (auto to : g[v]) {
            if (max(d[1][v] + 1, a[to]) < d[1][to]) {
                d[1][to] = max(d[1][v] + 1, a[to]);
                q.push({d[1][to], to});
            }
        }
    }

    int ans = inf;
    for (int i = 1; i <= n; i++) {
        ans = min(ans, d[0][i] + d[1][i] + abs(d[0][i] - d[1][i]));
    }
    for (int i = 1; i <= m; i++) {
        if (d[0][e[i].F] >= a[e[i].S]) ans = min(ans, d[0][e[i].F] + d[1][e[i].S] + abs(d[0][e[i].F] - d[1][e[i].S]) + 1);
        swap(e[i].F, e[i].S);
        if (d[0][e[i].F] >= a[e[i].S]) ans = min(ans, d[0][e[i].F] + d[1][e[i].S] + abs(d[0][e[i].F] - d[1][e[i].S]) + 1);
    }

    cout << ans;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int test = 1;
    // cin >> test;
    while (test--) {
        solve();
        // cout << '\n';
    }
    return 0;
}

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