Submission #1216087

#	Time	Username	Problem	Language	Result	Execution time	Memory
1216087		kiennguyendinh	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	2095 ms	20392 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
int n,m,S,T,U,V,x,y;
long long w;
vector<pair<int,pair<long long,int>>> adj[100001];
bool c[200001];
long long dist[2][100001];
int pre[2][100001];
void dik(int t,int sta){
    for(int i = 1;i <= n;i++) dist[t][i] = LLONG_MAX;
    dist[t][sta] = 0;
    queue<int> q;
    q.push(sta);
    while(!q.empty()){
        int u = q.front();
        q.pop();
        for(pair<int,pair<long long,int>> &v : adj[u]){
            if(c[v.second.second]){
                if(dist[t][v.first] > dist[t][u]){
                      dist[t][v.first] = dist[t][u];
                      pre[t][v.first] = u;
                      q.push(v.first);
                }
                continue;
            }
            if(dist[t][v.first] > dist[t][u] + v.second.first){
                dist[t][v.first] = dist[t][u] + v.second.first;
                q.push(v.first);
                pre[t][v.first] = u;
            }
        }
    }
}
long long res = LLONG_MAX;
void track(int t,int sta,int en){
    while(sta != en){
        //cout << sta << " - {";
        int u = pre[t][sta];
        long long d = dist[t][sta] - dist[t][u];
        for(pair<int,pair<long long,int>> &v : adj[u]){
            if(v.first == sta && d == v.second.first){
                c[v.second.second] = true;
                break;
            }
        }
        //cout << d << "} - ";
        sta = u;
    }
    //cout << en << "\n";
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    cin >> n >> m >> S >> T >> U >> V;
    for(int i = 1;i <= m;i++){
        cin >> x >> y >> w;
        adj[x].push_back({y,{w,i}});
        adj[y].push_back({x,{w,i}});
    }
    dik(0,S);
    track(0,T,S);
    dik(1,U);
    track(1,V,U);
    res = dist[1][V];
    //for(int i = 1;i <= m;i++) c[i] = false;
    //dik(1,U);
    //track(1,V,U);
    //dik(0,S);
    //res = min(res,dist[0][T]);
    cout << res;
    return 0;
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45