Submission #747128

#	Time	Username	Problem	Language	Result	Execution time	Memory
747128		1075508020060209tc	Olympic Bus (JOI20_ho_t4)	C++14	100 / 100	923 ms	5016 KiB

ho_t4

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

int n;int m;
int uar[50010];int var[50010];long long war[50010];long long dar[50010];
long long dis[210];
long long rdis[210];
int vis[210];
long long odis[210];
long long ordis[210];
vector<pair<int,long long>>e[210];
long long dijkstera(){
for(int i=1;i<=n;i++){
    dis[i]=1e18;
    vis[i]=0;
    rdis[i]=1e18;
    e[i].clear();
}
for(int i=1;i<=m;i++){
    e[uar[i]].push_back({var[i],war[i]});
}
 
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>pq;
dis[1]=0;
pq.push({0,1});
while(pq.size()){
    int nw=pq.top().second;
    pq.pop();
    if(vis[nw]){continue;}
    vis[nw]=1;
    for(int i=0;i<e[nw].size();i++){
        int v=e[nw][i].first;
        long long w=e[nw][i].second;
        if(dis[v]>dis[nw]+w){
            dis[v]=dis[nw]+w;
            pq.push({dis[v],v});
        }
    }
}
 
 
rdis[n]=0;
pq.push({0,n});
while(pq.size()){
    int nw=pq.top().second;
    pq.pop();
    if(vis[nw]==2){continue;}
    vis[nw]=2;
    for(int i=0;i<e[nw].size();i++){
        int v=e[nw][i].first;
        long long w=e[nw][i].second;
        if(rdis[v]>rdis[nw]+w){
            rdis[v]=rdis[nw]+w;
            pq.push({rdis[v],v});
        }
    }
}
return dis[n]+rdis[1];
}
vector<int>ee[210];
vector<int>er[210];
 
long long dis1[210];int frm[210];
long long rdis1[210];int frmn[210];
 
long long disn[210];
long long rdisn[210];
 
long long fdis[210][210];
int isin[50010];
signed main()
{
    cin.tie(0);
    ios_base::sync_with_stdio(0);
 
    cin>>n>>m;
 
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            fdis[i][j]=1e18;
        }
        fdis[i][i]=0;
    }
 
    for(int i=1;i<=m;i++){
        cin>>uar[i]>>var[i]>>war[i]>>dar[i];
        ee[uar[i]].push_back(i);
        er[var[i]].push_back(i);
        fdis[uar[i]][var[i]]=min(fdis[uar[i]][var[i]],war[i]);
    }
    for(int i=1;i<=n;i++){
        dis1[i]=1e18;
        rdis1[i]=1e18;
        disn[i]=1e18;
        rdisn[i]=1e18;
    }
 
    priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>pq;
    dis1[1]=0;
    pq.push({0,1});
    while(pq.size()){
        int nw=pq.top().second;
        pq.pop();
        if(vis[nw]){continue;}
        vis[nw]=1;
        for(int i=0;i<ee[nw].size();i++){
            int id=ee[nw][i];
            int v=var[id];int w=war[id];
            if(dis1[v]>dis1[nw]+w){
                dis1[v]=dis1[nw]+w;
                frm[v]=id;
                pq.push({dis1[v],v});
            }
        }
    }
    for(int i=1;i<=n;i++){
        vis[i]=0;
    }
    disn[n]=0;
    pq.push({0,n});
    while(pq.size()){
        int nw=pq.top().second;
        pq.pop();
        if(vis[nw]){continue;}
        vis[nw]=1;
        for(int i=0;i<ee[nw].size();i++){
            int id=ee[nw][i];
            int v=var[id];int w=war[id];
            if(disn[v]>disn[nw]+w){
                disn[v]=disn[nw]+w;
                frmn[v]=id;
                pq.push({disn[v],v});
            }
        }
    }
 
 
    for(int i=1;i<=n;i++){
        for(int a=1;a<=n;a++){
            for(int b=1;b<=n;b++){
                fdis[a][b]=min(fdis[a][b],fdis[a][i]+fdis[i][b]);
            }
        }
    }
    if(dis1[n]<1e18){
    int nw=n;
    while(nw!=1){
        int id=frm[nw];
        isin[id]=1;
        nw=uar[id];
    }
    }
    if(disn[1]<1e18){
    int nw=1;
    while(nw!=n){
        int id=frmn[nw];
        isin[id]=1;
        nw=uar[id];
    }
    }
 
    long long ans=dijkstera();
//cout<<"hihi\n";
    for(int i=1;i<=m;i++){
   //         cout<<i<<" ";
        if(isin[i]){
            swap(uar[i],var[i]);
            ans=min(ans,dijkstera()+dar[i]);
            swap(uar[i],var[i]);
        }else{
      //  continue;
            int a=uar[i];int b=var[i];
            long long cal=min(dis1[n],fdis[1][b]+war[i]+fdis[a][n] )+fdis[n][b]+fdis[a][1]+war[i];
            cal=min(cal,min(disn[1],fdis[n][b]+war[i]+fdis[a][1])+fdis[1][b]+fdis[a][n]+war[i] );
            ans=min(ans,cal+dar[i]);
 
        }
        //}
    //    cout<<ans<<endl;
    }
    if(ans>=1e18){ans=-1;}
cout<<ans<<endl;
 
 
 
}

Compilation message (stderr)

ho_t4.cpp: In function 'long long int dijkstera()':
ho_t4.cpp:31:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for(int i=0;i<e[nw].size();i++){
      |                 ~^~~~~~~~~~~~~
ho_t4.cpp:49:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |     for(int i=0;i<e[nw].size();i++){
      |                 ~^~~~~~~~~~~~~
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:106:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |         for(int i=0;i<ee[nw].size();i++){
      |                     ~^~~~~~~~~~~~~~
ho_t4.cpp:126:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  126 |         for(int i=0;i<ee[nw].size();i++){
      |                     ~^~~~~~~~~~~~~~

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