Submission #1104099

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104099		Champ_Naman	Olympic Bus (JOI20_ho_t4)	C++17	5 / 100	1083 ms	5912 KiB

ho_t4

#include<bits/stdc++.h>
#define int long long
using namespace std;

int Dijkstra(int a, int b, vector<multiset<pair<int,int>>>& g){
    int n = g.size();
	priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> pq;
	vector<int> dist(n, 1e18);
	vector<int> vis(n, 0);

	pq.push({0, a});
	dist[a] = 0;

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

		if(vis[v]) continue;
        vis[v] = 1;

		for(auto [ch, w] : g[v]){
			if(d + w < dist[ch]){
				dist[ch] = d + w;
				pq.push({dist[ch], ch});
			}
		}
	}

	return dist[b];
}

inline void solve(){
    int n, m;
    cin>>n>>m;

    vector<multiset<pair<int,int>>> g(n+1);
    vector<tuple<int,int,int,int>> e;
    vector<vector<int>> dist(n+1, vector<int>(n+1, 1e18));
    for(int i=1; i<=n; i++) dist[i][i] = 0;

    for(int i=0; i<m; i++){
        int u, v, c, d;
        cin>>u>>v>>c>>d;

        e.push_back({u, v, c, d});
        g[u].insert({v, c});
        dist[u][v] = min(dist[u][v], c);
    }

    for(int k=1; k<=n; k++){
        for(int i=1; i<=n; i++){
            for(int j=1; j<=n; j++){
                dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
            }
        }
    }

    int ans = dist[1][n] + dist[n][1];
    for(auto [u, v, c, d] : e){
        g[u].erase(g[u].find({v, c}));
        g[v].insert({u, c});

        ans = min(ans, d + Dijkstra(1, n, g) + Dijkstra(n, 1, g));

        g[v].erase(g[v].find({u, c}));
        g[u].insert({v, c});
    }
    
    cout<<(ans >= 1e18 ? -1 : ans);
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);cout.tie(NULL);

    int t = 1;
    //cin>>t;
    while(t--) solve();

    return 0;
}

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