Submission #1205390

#	Time	Username	Problem	Language	Result	Execution time	Memory
1205390		biank	Airplane (NOI23_airplane)	C++20	0 / 100	51 ms	21516 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#define forn(i,n) for(int i=0;i<int(n);i++)
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define dforn(i,n) for(int i=int(n)-1;i>=0;i--)
#define dforsn(i,s,n) for(int i=int(n)-1;i>=int(s);i--)
#define fst first
#define snd second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()

typedef long long ll;
typedef vector<ll> vll;
typedef vector<int> vi;
typedef pair<int,int> ii;

const ll INF=1e18;

pair<vll,vll> dijkstra(int s, vector<vi> &adj, vi &a){
    int n=sz(adj);
    vll dist(n,INF);
    vll height(n,INF);
    priority_queue<tuple<ll,int,int>> pq;
    pq.emplace(0,0,s);
    dist[s]=0,height[s]=0;
    vector<bool> vis(n,false);
    while(!pq.empty()){
        auto[d,h,u]=pq.top();
        pq.pop();
        for(int v:adj[u]){
            ll newH=max(h,a[v]);
            ll newD=dist[u]+max(newH-h,1LL);
            if(make_pair(-newD,-newH)>make_pair(-dist[v],-height[v])){
                dist[v]=newD,height[v]=newH;
                pq.emplace(-dist[v],height[v],v);
            }
        }
    }
    return {dist,height};
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    
    int n,m;
    cin>>n>>m;
    vi a(n);
    forn(i,n) cin>>a[i];
    vector<vi> adj(n);
    forn(i,m){
        int u,v;
        cin>>u>>v;
        --u,--v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    auto[distFromS,heightFromS]=dijkstra(0,adj,a);
    auto[distToT,heightToT]=dijkstra(n-1,adj,a);
    ll res=INF;
    forn(u,n){
        ll curr=max(distFromS[u],heightToT[u])+max(distToT[u],heightFromS[u]);
        res=min(res,curr);
        curr=distFromS[u]+distToT[u]+abs(heightToT[u]-heightFromS[u]);
        res=min(res,curr);
        for(int v:adj[u]){
            curr=max(distFromS[u],heightToT[v])+max(distToT[v],heightFromS[u])+1;
            res=min(res,curr);
            curr=distFromS[u]+distToT[v]+abs(heightToT[v]-heightFromS[u])+1;
            res=min(res,curr);
        }
    }
    cout<<res<<'\n';
    
    return 0;
}

• Subtask 1: 0 / 22
• Subtask 2: 0 / 10
• Subtask 3: 0 / 31
• Subtask 4: 0 / 37