Submission #736205

#	Time	Username	Problem	Language	Result	Execution time	Memory
736205		Ahmed57	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	358 ms	25980 KiB

commuter_pass

#include <bits/stdc++.h>

using namespace std;
long long cost[4][100001];
vector<pair<int,long long>> adj[100001];
void d(int s,int ty){
    priority_queue<pair<long long,long long>> q1;
    q1.push({0,s});
    cost[ty][s] = 0;
    while(!q1.empty()){
        long long co = q1.top().first*-1;
        long long no = q1.top().second;
        q1.pop();
        if (co>cost[ty][no]) continue ;
        for(int i= 0;i<adj[no].size();i++){
            if(cost[ty][adj[no][i].first]>(adj[no][i].second+co)){
                cost[ty][adj[no][i].first] = (adj[no][i].second+co);
                q1.push({cost[ty][adj[no][i].first]*-1,adj[no][i].first});
            }
        }
    }
}
long long dp[100001];
long long u,v,s,t,n,m,ans;
long long solve(int a,int ty){
    if(dp[a]!=-1)return dp[a];
    if(cost[2][a]+cost[3][a]==cost[2][t]){
        dp[a] = cost[1][a];
        for(auto j:adj[a]){
            if(ty?cost[2][a]+j.second==cost[2][j.first]:cost[3][a]+j.second==cost[3][j.first]){
                dp[a] = min(dp[a],solve(j.first,ty));
            }
        }
        ans = min(ans,dp[a]+cost[0][a]);
    }else dp[a] = 1e18;
    return dp[a];
}
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    cin>>n>>m;
    cin>>s>>t;
    cin>>u>>v;
    for(int i = 0;i<m;i++){
        int a,b,c;cin>>a>>b>>c;
        adj[a].push_back({b,c});
        adj[b].push_back({a,c});
    }
    for(int i = 0;i<=n;i++){
        cost[0][i] = 1e18;cost[1][i] = 1e18;
        cost[2][i] = 1e18;cost[3][i] = 1e18;
    }
    d(u,0);d(v,1);d(s,2);d(t,3);
    ans = cost[0][v];
    memset(dp,-1,sizeof dp);
    solve(t,0);
    memset(dp,-1,sizeof dp);
    solve(s,1);
    cout<<ans<<endl;
    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void d(int, int)':
commuter_pass.cpp:15:23: 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]
   15 |         for(int i= 0;i<adj[no].size();i++){
      |                      ~^~~~~~~~~~~~~~~

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