Submission #926560

#	Time	Username	Problem	Language	Result	Execution time	Memory
926560		irmuun	Cities (BOI16_cities)	C++17	100 / 100	4129 ms	44236 KiB

cities

#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int n,k,m;
    cin>>n>>k>>m;
    ll dp[32][n];
    int p[k];
    vector<pair<int,ll>>adj[n];
    for(int i=0;i<k;i++){
        cin>>p[i];
        p[i]--;
    }
    for(int i=0;i<m;i++){
        int a,b;
        ll c;
        cin>>a>>b>>c;
        a--,b--;
        adj[a].pb({b,c});
        adj[b].pb({a,c});
    }
    for(int i=0;i<(1<<k);i++){
        for(int j=0;j<n;j++){
            dp[i][j]=1e18;
        }
    }
    for(int i=0;i<k;i++){
        dp[1<<i][p[i]]=0;
    }
    for(int c=0;c<(1<<k);c++){
        for(int a=0;a<c;a++){
            if((a|c)!=c) continue;
            int b=a^c;
            if(b>a) continue;
            for(int i=0;i<n;i++){
                dp[c][i]=min(dp[c][i],dp[a][i]+dp[b][i]);
            }
        }
        set<pair<ll,int>>st;
        for(int i=0;i<n;i++){
            if(dp[c][i]<1e18){
                st.insert({dp[c][i],i});
            }
        }
        while(!st.empty()){
            auto [d,i]=*st.begin();
            st.erase(st.begin());
            for(auto [j,C]:adj[i]){
                ll cost=C+d;
                if(cost<dp[c][j]){
                    if(dp[c][j]<1e18){
                        st.erase({dp[c][j],j});
                    }
                    dp[c][j]=cost;
                    st.insert({dp[c][j],j});
                }
            }
        }
    }
    ll ans=1e18;
    for(int i=0;i<n;i++){
        ans=min(ans,dp[(1<<k)-1][i]);
    }
    cout<<ans;
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26