Submission #649868

#TimeUsernameProblemLanguageResultExecution timeMemory
649868UzoufCommuter Pass (JOI18_commuter_pass)C++14
24 / 100
141 ms262144 KiB
#include <bits/stdc++.h>
using namespace std;
#define int long long

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

    int n,m; cin>>n>>m;
    int s,t,u,v; cin>>s>>t>>u>>v;
    vector<vector<pair<int,int> > > vv(n+5);
    int fl1[n+5][n+5],fl2[n+5][n+5];

    for (int i=0;i<=n;i++) {
        for (int j=0;j<=n;j++) {
                fl1[i][j]=1e18; fl2[i][j]=1e18;
        }
        fl1[i][i]=0; fl2[i][i]=0;
    }

    for (int i=0;i<m;i++) {
        int a,b,c; cin>>a>>b>>c;
        vv[a].push_back({b,c});
        vv[b].push_back({a,c});
        fl1[a][b]=c; fl1[b][a]=c;
        fl2[a][b]=c; fl2[b][a]=c;
    }

    int diss[n+5],dist[n+5],disv[n+5],disu[n+5],par[n+5];
    for (int i=0;i<=n;i++) {
        diss[i]=dist[i]=disv[i]=disu[i]=1e18; par[i]=-1;
    }


    /*priority_queue<pair<int,int>,vector<pair<int,int> >,greater<pair<int,int> > > q;
    q.push({0,s}); diss[s]=0; par[s]=s;
    while (!q.empty()) {
        int c=q.top().first,i=q.top().second;
        q.pop();
        if (c>diss[i]) continue;
        for (int j=0;j<vv[i].size();j++) {
            int ii=vv[i][j].first,cc=vv[i][j].second;
            int nwc=c+cc;
            if (diss[ii]>nwc) {
                diss[ii]=nwc;
                q.push({nwc,ii});
                par[ii]=i;
            }
        }
    }

    q.push({0,t}); dist[t]=0;
    while (!q.empty()) {
        int c=q.top().first,i=q.top().second;
        q.pop();
        if (c>dist[i]) continue;
        for (int j=0;j<vv[i].size();j++) {
            int ii=vv[i][j].first,cc=vv[i][j].second;
            int nwc=c+cc;
            if (dist[ii]>nwc) {
                dist[ii]=nwc;
                q.push({nwc,ii});
            }
        }
    }

    int indx=t;
    while (indx!=s) {
        for (int i=0;i<vv[indx].size();i++) {
            if (vv[indx][i].first==par[indx]) vv[indx][i].second=0;
        }
        for (int i=0;i<vv[par[indx]].size();i++) {
            if (vv[par[indx]][i].first==indx) vv[par[indx]][i].second=0;
        }
        fl2[indx][par[indx]]=0; fl2[par[indx]][indx]=0;
        indx=par[indx];
    }


    q.push({0,v}); disv[v]=0;
    while (!q.empty()) {
        int c=q.top().first,i=q.top().second;
        q.pop();
        if (c>disv[i]) continue;
        for (int j=0;j<vv[i].size();j++) {
            int ii=vv[i][j].first,cc=vv[i][j].second;
            int nwc=c+cc;
            if (disv[ii]>nwc) {
                disv[ii]=nwc;
                q.push({nwc,ii});
            }
        }
    }

    q.push({0,u}); disu[u]=0;
    while (!q.empty()) {
        int c=q.top().first,i=q.top().second;
        q.pop();
        if (c>disu[i]) continue;
        for (int j=0;j<vv[i].size();j++) {
            int ii=vv[i][j].first,cc=vv[i][j].second;
            int nwc=c+cc;
            if (disu[ii]>nwc) {
                disu[ii]=nwc;
                q.push({nwc,ii});
            }
        }
    }

    if (s!=u) {
            cout<<disv[u]; return 0;
    }
    //--------------------------------------
    int ans=1e18;
    for (int i=1;i<=n;i++) {
        if (diss[i]+dist[i]==diss[t]) {
            ans=min(ans,disv[i]);
        }
    }
    if (n>300) {
            cout<<ans; return 0;
    }*/
    //---------------------------------------
    for(int k=1;k<=n;k++) {
        for (int i=1;i<=n;i++) {
            for (int j=1;j<=n;j++) {
                fl1[i][j]=min(fl1[i][j],fl1[i][k]+fl1[k][j]);
                fl2[i][j]=min(fl2[i][j],fl2[i][k]+fl2[k][j]);
            }
        }
    }
    int ans=fl1[u][v];
    for (int i=1;i<=n;i++) {
        for (int j=1;j<=n;j++) {
            if (fl1[s][i]+fl1[i][j]+fl1[j][t]==fl1[s][t] || fl1[s][j]+fl1[j][i]+fl1[i][t]==fl1[s][t]) {
                ans=min({ans,fl1[u][i]+fl1[j][v],fl1[u][j]+fl1[i][v]});
              }
            }
        }

    cout<<ans;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:28:9: warning: variable 'diss' set but not used [-Wunused-but-set-variable]
   28 |     int diss[n+5],dist[n+5],disv[n+5],disu[n+5],par[n+5];
      |         ^~~~
commuter_pass.cpp:28:49: warning: variable 'par' set but not used [-Wunused-but-set-variable]
   28 |     int diss[n+5],dist[n+5],disv[n+5],disu[n+5],par[n+5];
      |                                                 ^~~
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