Submission #485771

#	Time	Username	Problem	Language	Result	Execution time	Memory
485771		Jarif_Rahman	Olympic Bus (JOI20_ho_t4)	C++17	5 / 100	1094 ms	3000 KiB

ho_t4

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
const ll inf = 1e17;
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, m; cin >> n >> m;

    vector<array<int, 4>> edges(m);
    for(int i = 0; i < m; i++){
        cin >> edges[i][0] >> edges[i][1] >> edges[i][2] >> edges[i][3];
        edges[i][0]--, edges[i][1]--;
    }

    ll ans = inf;

    for(int tt = 0; tt <= m; tt++){
        vector<vector<pair<int, ll>>> v(n);
        ll cur = 0;
        for(int i = 0; i < m; i++){
            if(tt == i){
                v[edges[i][1]].pb({edges[i][0], edges[i][2]});
                cur+=edges[i][3];
            }
            else{
                v[edges[i][0]].pb({edges[i][1], edges[i][2]});
            }
        }

        priority_queue<pair<ll, int>> pq;
        vector<ll> dis(n, inf);
        vector<bool> bl(n, 0);
        dis[0] = 0;
        pq.push({0, 0});

        while(!pq.empty()){
            int nd = pq.top().sc; pq.pop();
            if(bl[nd]) continue;
            bl[nd] = 1;
            for(auto [x, w]: v[nd]) if(dis[nd]+w < dis[x]){
                dis[x] = dis[nd]+w;
                pq.push({-dis[x], x});
            }
        }

        cur+=dis[n-1];
        cur = min(cur, inf);

        bl.assign(n, 0);
        dis.assign(n, inf);

        dis[n-1] = 0;
        pq.push({0, n-1});

        while(!pq.empty()){
            int nd = pq.top().sc; pq.pop();
            if(bl[nd]) continue;
            bl[nd] = 1;
            for(auto [x, w]: v[nd]) if(dis[nd]+w < dis[x]){
                dis[x] = dis[nd]+w;
                pq.push({-dis[x], x});
            }
        }

        cur+=dis[0];

        ans = min(ans, cur);
    }

    if(ans >= inf) ans = -1;
    cout << ans << "\n";

}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63