Submission #1252730

#	Time	Username	Problem	Language	Result	Execution time	Memory
1252730		Geforgs	Airplane (NOI23_airplane)	C++20	100 / 100	376 ms	27048 KiB

Main

#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <unordered_map>
#include <stack>
#include <bit>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#define ll long long
#define ld long double
#define inf (ll)(2*1e18)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define pb push_back
#define endl "\n"
using namespace std;

void Dijkstra(ll start, vector<ll>& a, vector<vector<ll>>& b, vector<ll>& dis){
    set<pair<ll, ll>> s;
    s.insert({0, start});
    dis[start] = 0;
    while(!s.empty()){
        auto [val, x] = *s.begin();
        s.erase(s.begin());
        for(auto y: b[x]){
            if(dis[y] > max(a[y], val+1)){
                s.erase({dis[y], y});
                dis[y] = max(a[y], val+1);
                s.insert({dis[y], y});
            }
        }
    }
}

void solve(){
    ll n, m, i, x, y, res=inf;
    cin>>n>>m;
    vector<ll> a(n);
    vector<vector<ll>> b(n);
    vector<ll> dis1(n, inf);
    vector<ll> dis2(n, inf);
    for(i=0;i<n;++i){
        cin>>a[i];
    }
    for(i=0;i<m;++i){
        cin>>x>>y;
        --x;
        --y;
        b[x].pb(y);
        b[y].pb(x);
    }
    Dijkstra(0, a, b, dis1);
    Dijkstra(n-1, a, b, dis2);
    for(i=0;i<n;++i){
        res = min(res, 2*max(dis1[i], dis2[i]));
        for(auto el: b[i]){
            if(dis1[i] == dis2[el]){
                res = min(res, 2*dis1[i] + 1);
            }
        }
    }
    cout<<res<<endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    srand(time(nullptr));
    ll t=1;
//    cin>>t;
    for(;t>0;--t){
        solve();
    }
    return 0;
}

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