제출 #260894

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
260894		SorahISA	철인 이종 경기 (APIO18_duathlon)	C++17	8 / 100	62 ms	4856 KiB

count_triplets

#pragma GCC optimize("Ofast", "unroll-loops")
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define double long double
using pii = pair<int, int>;
template<typename T>
using prior = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using Prior = priority_queue<T>;

#define X first
#define Y second
#define ALL(x) (x).begin(), (x).end()
#define eb emplace_back
#define pb push_back
#define fastIO() ios_base::sync_with_stdio(false), cin.tie(0)

const int maxn = 1E5 + 5;

vector<int> p(maxn), sz(maxn, 1);

int R(int x) {return x ^ p[x] ? p[x] = R(p[x]) : x;}
void U(int x, int y) {if (R(x) ^ R(y)) sz[R(y)] += sz[R(x)], p[R(x)] = R(y);}

int32_t main() {
    fastIO();
    iota(ALL(p), 0);
    
    int n, m, ans = 0;
    cin >> n >> m;
    
    int u[m], v[m];
    for (int i = 0; i < m; ++i) {
        cin >> u[i] >> v[i], U(u[i], v[i]);
    }
    
    map<int, int> cnt;
    for (int i = 0; i < m; ++i) {
        ++cnt[R(u[i])];
    }
    
    for (auto [idx, val] : cnt) {
        if (val == sz[idx]) ans += sz[idx] * (sz[idx] - 1) * (sz[idx] - 2);
        else ans += sz[idx] * (sz[idx] - 1) * (sz[idx] - 2) / 3;
    }
    
    cout << ans << "\n";
    
    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