Submission #952861

#	Time	Username	Problem	Language	Result	Execution time	Memory
952861		sondos225	Relay Marathon (NOI20_relaymarathon)	C++17	100 / 100	5538 ms	176852 KiB

RelayMarathon

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T>using ordered_set = tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;//find_by_order(ind);
//order_of_key()
//#define int long long
#define fast ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
#define pb push_back
#define yes "YES"
#define no "NO"
#define bigg INT_MAX
#define debug(x) cout<<(#x)<<" = " <<x<<endl;
#define all(x) x.begin(),x.end()
#define sz size()
#define nn '\n'
#define mms(x,y) memset(x,y,sizeof(x))
#define forr(i,j,n) for (int i=j; i<n; i++)
#define forn(i,j,n) for (int i=j; i>n; i--)
#define fi first
#define se second
#define la "LA"
#define cinn(x,y) for(int i=0; i<y; i++) cin>>x[i];
#define pii pair<int,int>
int par[100005];
bool b[100005];
int fin(int x)
{
    if (b[par[x]]) return par[x];
    return par[x]=fin(x);
}
signed main()
{
//    #ifndef LOCAL
//    freopen("lifeguards.in","r",stdin);
//    freopen("lifeguards.out","w", stdout);
//    #endif
    fast
    int n,m,k;
    cin>>n >>m >>k;
    vector<pii> a[n+1];
    forr(i,0,m)
    {
        int x,y,z;
        cin>>x >>y >>z;
        a[x].pb({y,z});
        a[y].pb({x,z});
    }
    int s[k];
    priority_queue<array<int,3>> q;
    forr(i,0,k)
    {
        cin>>s[i];
        q.push({0,s[i],s[i]});
        b[s[i]]=1;
        par[s[i]]=s[i];
    }
    //set <pii>vis;
    set<int> vis[n+1];
    int ans1=0;
    int a1=0, a2=0;
    while(!q.empty())
    {
        int c=q.top()[0], x=q.top()[1], last=q.top()[2];
        q.pop();
        if (vis[x].find(fin(last))!=vis[x].end()) continue;
        par[x]=fin(last);
        //  cout<<c<<' '<<x<<endl;
        if (b[x] && c!=0)
        {
            //    cout<<x<<' '<<c<<endl;
            ans1=-c;
            a1=x;
            a2=par[x];
            break;
        }
        // if (!b[x])
        vis[x].insert(par[x]);
//       cout<<"PUT"<<x<<' '<<last<<endl;
        for(auto y:a[x])
        {
//            cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
            if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi)
            {
                int o=abs(c);
                o+=y.se;
                q.push({-o,y.fi,par[x]});

                //     cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
            }
        }
    }
    /////
    ///new1
    while(!q.empty()) q.pop();
    // q.clear();
    forr(i,1,n+1) vis[i].clear();
    mms(par,0);
    forr(i,0,k)
    {
        //cin>>s[i];
        if (s[i]==a1 || s[i]==a2) continue;
        q.push({0,s[i],s[i]});
        //  b[s[i]]=1;
        par[s[i]]=s[i];
        // last[s[i]]=s[i];
    }
    ///////////////
    while(!q.empty())
    {
        int c=q.top()[0], x=q.top()[1], last=q.top()[2];
        q.pop();
        if (vis[x].find(fin(last))!=vis[x].end()) continue;
        par[x]=fin(last);
        //  cout<<c<<' '<<x<<endl;
        if (b[x] && c!=0)
        {
            //    cout<<x<<' '<<c<<endl;
            ans1+=(-c);
            // a1=x;
            // a2=par[x];
            break;
        }
        // if (!b[x])
        vis[x].insert(par[x]);
//       cout<<"PUT"<<x<<' '<<last<<endl;
        for(auto y:a[x])
        {
//            cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
            if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi && y.fi!=a1 && y.fi!=a2)
            {
                int o=abs(c);
                o+=y.se;
                q.push({-o,y.fi,par[x]});

                //     cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
            }
        }
    }
    /////////////////
    ///ans1 done
    /////
    ///new2
    while(!q.empty()) q.pop();
    // q.clear();
    forr(i,1,n+1) vis[i].clear();
    mms(par,0);
    forr(i,0,k)
    {
        //cin>>s[i];
        if (s[i]==a1) continue;
        q.push({0,s[i],s[i]});
        //  b[s[i]]=1;
        par[s[i]]=s[i];
        // last[s[i]]=s[i];
    }
    ///////////////
    int ans2=0;
    int b1=0, b2=0;
    while(!q.empty())
    {
        int c=q.top()[0], x=q.top()[1], last=q.top()[2];
        q.pop();
        if (vis[x].find(fin(last))!=vis[x].end()) continue;
        par[x]=fin(last);
        //  cout<<c<<' '<<x<<endl;
        if (b[x] && c!=0)
        {
            //    cout<<x<<' '<<c<<endl;
            ans2=(-c);
            b1=x;
            b2=par[x];
            break;
        }
        // if (!b[x])
        vis[x].insert(par[x]);
//       cout<<"PUT"<<x<<' '<<last<<endl;
        for(auto y:a[x])
        {
//            cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
            if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi && y.fi!=a1)
            {
                int o=abs(c);
                o+=y.se;
                q.push({-o,y.fi,par[x]});

                //     cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
            }
        }
    }
    /////////////////
    //new22
    while(!q.empty()) q.pop();
    // q.clear();
    forr(i,1,n+1) vis[i].clear();
    mms(par,0);
    forr(i,0,k)
    {
        //cin>>s[i];
        if (s[i]==a1) continue;
        q.push({0,s[i],s[i]});
        //  b[s[i]]=1;
        par[s[i]]=s[i];
        // last[s[i]]=s[i];
    }
    ///////////////
    // int ans2=0;
    //int b1=0, b2=0;
    while(!q.empty()) q.pop();
    // q.clear();
    forr(i,1,n+1) vis[i].clear();
    mms(par,0);
    forr(i,0,k)
    {
        //cin>>s[i];
        if (s[i]==b1 || s[i]==b2) continue;
        q.push({0,s[i],s[i]});
        //  b[s[i]]=1;
        par[s[i]]=s[i];
        // last[s[i]]=s[i];
    }
    while(!q.empty())
    {
        int c=q.top()[0], x=q.top()[1], last=q.top()[2];
        q.pop();
        if (vis[x].find(fin(last))!=vis[x].end()) continue;
        par[x]=fin(last);
        //  cout<<c<<' '<<x<<endl;
        if (b[x] && c!=0)
        {
            //    cout<<x<<' '<<c<<endl;
            ans2+=(-c);
            //  b1=x;
            // b2=par[x];
            break;
        }
        // if (!b[x])
        vis[x].insert(par[x]);
//       cout<<"PUT"<<x<<' '<<last<<endl;
        for(auto y:a[x])
        {
//            cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
            if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi && y.fi!=b1 && y.fi!=b2)
            {
                int o=abs(c);
                o+=y.se;
                q.push({-o,y.fi,par[x]});

                //     cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
            }
        }
    }
    ///ans2 done
    cout<<min(ans1,ans2);
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 12 / 12
• Subtask 3: 25 / 25
• Subtask 4: 58 / 58