제출 #572848

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
572848		jasmin	Shortcut (IOI16_shortcut)	C++14	0 / 100	1 ms	308 KiB

shortcut

#include<bits/stdc++.h>
#include "shortcut.h"

using namespace std;
const long long inf=1e18;

int farthest(int a, vector<vector<pair<int,int> > >& adi, int n){
    vector<long long> dist(n, inf);
    vector<bool> vis(n);
    dist[a]=0;
    priority_queue<pair<int,int> > pq;
    pq.push({-0, a});

    int ans=a;
    while(!pq.empty()){
        int v=pq.top().second;
        pq.pop();

        if(vis[v]) continue;
        vis[v]=true;
        ans=v;

        for(auto u: adi[v]){
            if(dist[v]+u.second<dist[u.first]){
                dist[u.first]=dist[v]+u.second;
                pq.push({-dist[u.first], u.first});
            }
        }
    }
    return dist[ans];
}

int diameter(int n, vector<vector<pair<int,int> > >& adi){
    int ans=0;
    for(int i=0; i<n; i++){
        ans=max(ans, farthest(i, adi, n));
    }
    return ans;
}

long long find_shortcut(int n, std::vector<int> l, std::vector<int> d, int c)
{
    vector<vector<pair<int,int> > > adi(n*2);
    for(int i=0; i<n-1; i++){
        adi[i].push_back({i+1, l[i]});
        adi[i+1].push_back({i, l[i]});
    }
    for(int i=0; i<n; i++){
        adi[i].push_back({i+n, d[i]});
        adi[i+n].push_back({i, d[i]});
    }

    int best=diameter(n*2, adi);
    for(int i=0; i<n; i++){
        for(int j=i+1; j<n; j++){

            adi[i].push_back({j, c});
            adi[j].push_back({i, c});
            /*if(diameter(n*2, adi)<best){
                cout << "=> " << diameter(n*2, adi) << " " << i << " " << j << "\n";
            }*/
            best=min(best, diameter(n*2, adi));
            adi[i].pop_back();
            adi[j].pop_back();

        }
    }
    return best;
}

/*signed main(){
    int n;
    cin >> n;
    vector<int> l(n-1);
    for(int i=0; i<n-1; i++){
        cin >> l[i];
    }
    vector<int> d(n);
    for(int i=0; i<n; i++){
        cin >> d[i];
    }
    int c;
    cin >> c; 

    cout << find_shortcut(n, l, d, c) << "\n";
}*/

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3