Submission #70817

#	Time	Username	Problem	Language	Result	Execution time	Memory
70817		3zp	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	1115 ms	75320 KiB

commuter_pass

#include<bits/stdc++.h>
#define mn 100009
#define pb push_back
using namespace std;
long  long n, m, S, T, U, V;
long  long f[mn];
vector<long long> v[mn], l[mn];
void Dij(long  long  k, long  long  *D){
    priority_queue<pair<long long,long long> > q;
    q.push({0,k});
    for(long  long  i = 1; i <= n; i++)
        D[i] = 1e18, f[i] = 0;
    D[k] = 0;
    while(q.size()){
        long  long  x = q.top().second;
        q.pop();
        if(f[x]) continue;
        f[x] = 1;
        for(long long i = 0; i < v[x].size(); i++){
            if(f[v[x][i]] == 0 &&
               D[v[x][i]] > D[x] + l[x][i]){
                    D[v[x][i]] = D[x] + l[x][i];
                    q.push({-D[v[x][i]], v[x][i]});
               }
        }
    }
}
long long  du[mn], dv[mn], ds[mn], dt[mn], mindu[mn], mindv[mn];
void specDIJ(){
    priority_queue<pair<long long,long long> > q;
    q.push({0,T});
    for(long long i = 1; i <= n; i++)
        dt[i] = 1e18, mindu[i] = du[i], mindv[i] = dv[i] ,f[i] = 0;
    dt[T] = 0;
    while(q.size()){
        long long x = q.top().second;
        q.pop();
        if(f[x]) continue;
        f[x] = 1;
        for(long long i = 0; i < v[x].size(); i++){
            long long p = v[x][i];
            if(dt[p] > dt[x] + l[x][i]){
                    dt[p] = dt[x] + l[x][i];
                    mindu[p] = min(mindu[x], du[p]);
                    mindv[p] = min(mindv[x], dv[p]);
                    q.push({-dt[p], p});
               }
            if(dt[p] == dt[x] + l[x][i]){
                    mindu[p] = min(mindu[p], mindu[x]);
                    mindv[p] = min(mindv[p], mindv[x]);
            }
        }
    }
}
main(){
    cin >> n >> m >> S >> T >> U >> V;
    for(long  long i = 0 ;i < m; i++){
        long  long a, b, c;
        cin >> a>> b >> c;
        v[a].pb(b);
        v[b].pb(a);
        l[a].pb(c);
        l[b].pb(c);
    }
    Dij(S,ds);
    Dij(U,du);
    Dij(V,dv);
    specDIJ();
    long  long  ans = 1e18;
    for(long  long i = 1; i <= n; i++){
        if(ds[i] + dt[i] == ds[T]){
            ans = min(ans, dv[i] + mindu[i]);
            ans = min(ans, du[i] + mindv[i]);
        }
    }
    cout << min(ans, du[V]) << endl;
 
 
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void Dij(long long int, long long int*)':
commuter_pass.cpp:19:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(long long i = 0; i < v[x].size(); i++){
                              ~~^~~~~~~~~~~~~
commuter_pass.cpp: In function 'void specDIJ()':
commuter_pass.cpp:40:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(long long i = 0; i < v[x].size(); i++){
                              ~~^~~~~~~~~~~~~
commuter_pass.cpp: At global scope:
commuter_pass.cpp:55:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^

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