結果
| 問題 | 
                            No.488 四角関係
                             | 
                    
| コンテスト | |
| ユーザー | 
                             penguinshunya
                         | 
                    
| 提出日時 | 2019-07-18 08:59:24 | 
| 言語 | C++17  (gcc 13.3.0 + boost 1.87.0)  | 
                    
| 結果 | 
                             
                                AC
                                 
                             
                            
                         | 
                    
| 実行時間 | 2,017 ms / 5,000 ms | 
| コード長 | 3,098 bytes | 
| コンパイル時間 | 2,546 ms | 
| コンパイル使用メモリ | 211,912 KB | 
| 最終ジャッジ日時 | 2025-01-07 07:18:40 | 
| 
                            ジャッジサーバーID (参考情報)  | 
                        judge3 / judge3 | 
(要ログイン)
| ファイルパターン | 結果 | 
|---|---|
| sample | AC * 3 | 
| other | AC * 22 | 
ソースコード
#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < int(n); i++)
#define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define reps(i, n) for (int i = 1; i <= int(n); i++)
#define rreps(i, n) for (int i = int(n); i >= 1; i--)
#define repc(i, n) for (int i = 0; i <= int(n); i++)
#define rrepc(i, n) for (int i = int(n); i >= 0; i--)
#define repi(i, a, b) for (int i = int(a); i < int(b); i++)
#define repic(i, a, b) for (int i = int(a); i <= int(b); i++)
#define each(x, y) for (auto &x : y)
#define all(a) (a).begin(), (a).end()
#define bit(b) (1ll << (b))
using namespace std;
using i32 = int;
using i64 = long long;
using u64 = unsigned long long;
using f80 = long double;
using vi32 = vector<i32>;
using vi64 = vector<i64>;
using vu64 = vector<u64>;
using vf80 = vector<f80>;
using vstr = vector<string>;
inline void yes() { cout << "Yes" << '\n'; exit(0); }
inline void no() { cout << "No" << '\n'; exit(0); }
inline i64 gcd(i64 a, i64 b) { if (min(a, b) == 0) return max(a, b); if (a % b == 0) return b; return gcd(b, a % b); }
inline i64 lcm(i64 a, i64 b) { return a / gcd(a, b) * b; }
inline u64 xorshift() { static u64 x = 88172645463325252ull; x = x ^ (x << 7); return x = x ^ (x >> 9); }
void solve(); int main() { ios::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(16); solve(); return 0; }
template <typename T> class pqasc : public priority_queue<T, vector<T>, greater<T>> {};
template <typename T> class pqdesc : public priority_queue<T, vector<T>, less<T>> {};
template <typename T> inline void amax(T &x, T y) { if (x < y) x = y; }
template <typename T> inline void amin(T &x, T y) { if (x > y) x = y; }
template <typename T> inline T power(T x, i64 n, T e = 1) { T r = e; while (n > 0) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; }
template <typename T> istream& operator>>(istream &is, vector<T> &v) { each(x, v) is >> x; return is; }
template <typename T> ostream& operator<<(ostream &os, vector<T> &v) { rep(i, v.size()) { if (i) os << ' '; os << v[i]; } return os; }
template <typename T, typename S> istream& operator>>(istream &is, pair<T, S> &p) { is >> p.first >> p.second; return is; }
template <typename T, typename S> ostream& operator<<(ostream &os, pair<T, S> &p) { os << p.first << ' ' << p.second; return os; }
void solve() {
	int N, M; cin >> N >> M;
	vector<vector<int>> w(N, vector<int>(N, 1e9));
	rep(i, N) w[i][i] = 0;
	rep(i, M) {
		int a, b; cin >> a >> b;
		w[a][b] = w[b][a] = 1;
	}
	rep(k, N) rep(i, N) rep(j, N) amin(w[i][j], w[i][k] + w[k][j]);
	int ans = 0;
	set<tuple<int, int, int, int>> tu;
	rep(i, N) rep(j, N) rep(k, N) rep(l, N) {
		set<int> se;
		se.insert(i);
		se.insert(j);
		se.insert(k);
		se.insert(l);
		vector<int> v;
		each(s, se) v.push_back(s);
		if (tu.count(make_tuple(v[0], v[1], v[2], v[3]))) continue;
		if (se.size() != 4) continue;
		if (w[i][j] != 1) continue;
		if (w[i][k] != 2) continue;
		if (w[i][l] != 1) continue;
		if (w[j][k] != 1) continue;
		if (w[j][l] != 2) continue;
		if (w[k][l] != 1) continue;
		ans++;
		tu.emplace(v[0], v[1], v[2], v[3]);
	}
	cout << ans << '\n';
}
            
            
            
        
            
penguinshunya