제출 #771818

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
771818		CyberCow	철인 이종 경기 (APIO18_duathlon)	C++17	0 / 100	29 ms	10972 KiB

count_triplets

//#include <bits/stdc++.h>
#include <random>
#include <algorithm>
#include <bitset>
#include <chrono>
#include <cmath>
#include <deque>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <chrono>
#define fr first
#define sc second
#define ad push_back
using namespace std;
using ll = long long;
mt19937 rnd(348502);
const int N = 300005;
vector<int> v[N];
int color[N];

ll st = 0, sz = 0;

void Dfs(int g, int p)
{
    sz++;
    color[g] = 1;
    for (auto to : v[g])
    {
        if (to != p)
        {
            if (color[to] == 1)
                st = 1;
        }
    }
}

void solve()
{
    int n, i, j, x, y, m;
    cin >> n >> m;
    for ( i = 0; i < m; i++)
    {
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    ll ans = 0;
    for ( i = 1; i <= n; i++)
    {
        sz = 0; st = 0;
        Dfs(i, -1);
        if (st == 1)
        {
            ans += sz * (sz - 1) * (sz - 2);
        }
        else if(sz >= 3)
        {
            ans += sz * (sz - 1) * (sz - 2) / 3;
        }
    }
    cout << ans;
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    ll tt = 1;
    //cin >> tt;
    while (tt--) {
        solve();
    }
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

count_triplets.cpp: In function 'void solve()':
count_triplets.cpp:49:15: warning: unused variable 'j' [-Wunused-variable]
   49 |     int n, i, j, x, y, m;
      |               ^

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 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