Submission #864566

#	Time	Username	Problem	Language	Result	Execution time	Memory
864566		vnm06	Duathlon (APIO18_duathlon)	C++14	8 / 100	34 ms	15456 KiB

count_triplets

#include<bits/stdc++.h>
#define endl '\n'

using namespace std;

long long n, m, brv=0, sumst=0;
bool used[300005];
vector<int> gr[300005];

void dfs(int v)
{
    used[v]=1;
    brv++;
    int brs=gr[v].size();
    sumst+=brs;
    for(int i=0; i<brs; i++)
    {
        if(used[gr[v][i]]) continue;
        dfs(gr[v][i]);
    }
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>m;
    for(int i=0; i<m; i++)
    {
        int v, u;
        cin>>v>>u;
        gr[v].push_back(u);
        gr[u].push_back(v);
    }
    long long ans=0;
    for(int i=1; i<=n; i++)
    {
        if(used[i]) continue;
        brv=0;
        sumst=0;
        dfs(i);
        if(sumst==2*brv) ans+=brv*(brv-1)*(brv-2);
        else ans+=brv*(brv-1)*(brv-2)/3;
    }
    cout<<ans<<endl;
    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 8 / 8
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10