제출 #259107

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
259107		_7_7_	철인 이종 경기 (APIO18_duathlon)	C++14	0 / 100	65 ms	11024 KiB

count_triplets

#include <bits/stdc++.h>                                           
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
//#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
 
 
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define fastio ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
 
 
 
 
typedef pair < long long, long long > pll;    
typedef pair < int, int > pii;  
typedef unsigned long long ull;         
typedef vector < pii > vpii;                                   	
typedef vector < int > vi;
typedef long double ldb;  
typedef long long ll;  
typedef double db;
 
typedef tree < int, null_type, less < int >, rb_tree_tag, tree_order_statistics_node_update > ordered_set;
 
const int inf = 1e9, maxn = 2e5 + 48, mod = 998244353, N = 1e5 + 12;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 300;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = acos(-1);
const ll INF = 1e18;
 

int n, m, v, u, cnt;
bool cycle, was[N];
vi g[N];
ll ans;

void dfs (int v, int p = 0) {
	was[v] = 1;
	++cnt;

	for (auto to : g[v])
		if (to != p) {
			if (was[to])
				cycle = 1;
			else
				dfs(to, v);
		}
}


main () {
	fastio
	cin >> n >> m;
	while (m--) {
		cin >> v >> u;
		g[v].pb(u);
		g[u].pb(v);
	}

	for (int i = 1; i <= n; ++i)	
		if (!was[i]) {
		    cnt = 0, cycle = 0;
			dfs(i); 
			if (!cycle)
				ans += cnt * 1ll * (cnt - 1) * (cnt - 2) / 6;
			else
				ans += cnt * 1ll * (cnt - 1) * (cnt - 2) / 3;				
		}

	cout << ans << endl;
}

컴파일 시 표준 에러 (stderr) 메시지

count_triplets.cpp:64:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^

• 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