Submission #926423

#	Time	Username	Problem	Language	Result	Execution time	Memory
926423		irmuun	Cities (BOI16_cities)	C++17	15 / 100	1248 ms	262144 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()

struct dsu{
    vector<ll>p,sz;
    dsu(ll n){
        p.resize(n+1);
        iota(p.begin(),p.end(),0);
        sz.resize(n+1);
        fill(sz.begin(),sz.end(),1);
    }
    ll find(ll x){
        if(p[x]==x){
            return x;
        }
        return p[x]=find(p[x]);
    }
    bool same(ll x,ll y){
        x=find(x);
        y=find(y);
        if(x==y){
            return true;
        }
        else{
            return false;
        }
    }
    void merge(ll x,ll y){
        x=find(x);
        y=find(y);
        if(x!=y){
            if(sz[x]<sz[y]){
                swap(x,y);
            }
            sz[x]+=sz[y];
            p[y]=x;
        }
    }
};

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    ll n,k,m;
    cin>>n>>k>>m;
    ll dist[n+5],p[k+5];
    for(ll i=1;i<=k;i++){
        cin>>p[i];
        p[i]--;
    }
    vector<pair<ll,ll>>adj[n+5];
    vector<array<ll,3>>edge;
    ll D[n+5][n+5];
    for(ll i=0;i<n;i++){
        for(ll j=0;j<m;j++){
            D[i][j]=1e18;
        }
        D[i][i]=0;
    }
    for(ll i=1;i<=m;i++){
        ll a,b,c;
        cin>>a>>b>>c;
        a--,b--;
        edge.pb({c,a,b});
        adj[a].pb({b,c});
        adj[b].pb({a,c});
        D[a][b]=c;
        D[b][a]=c;
    }
    for(ll r=0;r<n;r++){
        for(ll i=0;i<n;i++){
            for(ll j=0;j<n;j++){
                if(D[i][r]<1e18&&D[r][j]<1e18){
                    D[i][j]=min(D[i][j],D[i][r]+D[r][j]);
                }
            }
        }
    }
    sort(all(edge));
    ll ans=1e18;
    for(ll i=0;i<n;i++){
        ll cur=0;
        for(ll j=1;j<=k;j++){
            cur+=D[i][p[j]];
        }
        ans=min(ans,cur);
    }
    if(k==4){
        for(ll i=0;i<n;i++){
            for(ll j=0;j<n;j++){
                ll cur=min({
                    D[p[1]][i]+D[p[2]][i]+D[p[3]][j]+D[p[4]][j],
                    D[p[1]][i]+D[p[2]][j]+D[p[3]][i]+D[p[4]][j],
                    D[p[1]][j]+D[p[2]][i]+D[p[3]][i]+D[p[4]][j],
                    D[p[1]][i]+D[p[2]][j]+D[p[3]][j]+D[p[4]][i],
                    D[p[1]][j]+D[p[2]][i]+D[p[3]][j]+D[p[4]][i],
                    D[p[1]][j]+D[p[2]][j]+D[p[3]][i]+D[p[4]][i],
                });
                ans=min(ans,cur+D[i][j]);
            }
        }
    }
    cout<<ans;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:53:8: warning: unused variable 'dist' [-Wunused-variable]
   53 |     ll dist[n+5],p[k+5];
      |        ^~~~

• Subtask 1: 0 / 22
• Subtask 2: 0 / 14
• Subtask 3: 15 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 26