Submission #516902

#	Time	Username	Problem	Language	Result	Execution time	Memory
516902		mansur	Duathlon (APIO18_duathlon)	C++17	5 / 100	79 ms	28996 KiB

count_triplets

#include<bits/stdc++.h>	
 
#pragma optimize ("g",on)
#pragma GCC optimize ("inline")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize ("03")
#pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
#pragma comment(linker, "/stack:200000000")
 
//01001101 01100001 01101011 01101000 01100001  01100111 01100001 01111001 
 
using namespace std;
 
#define all(a) a.begin(), a.end()                                                   
#define rall(a) a.rbegin(), a.rend()
#define ll long long
#define pb push_back
#define sz(a) a.size()
#define nl '\n'
#define popb pop_back()                                                                   
#define ld double
#define ull unsigned long long
#define ff first                                         
#define ss second  
#define fix fixed << setprecision
#define pii pair<int, int>                          
#define E exit (0)
#define int long long
 
const int inf = 1e15, N = 1e6, mod = 998244353;                    
 
double eps = 1e-6;
 
vector<pii> dir = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
 
bool can[(1 << 10)][10][10], was[N];

vector<int> h[10][10], adj[N];

int d, v;
 
void dfs(int u) {
	was[u] = 1;
	v++;
	for (auto e: adj[u]) {
		d++;
		if (!was[e]) {
			dfs(e);
		}
	}
}

main() {                                                         
	//freopen("F.in", "r", stdin);                                                                                     
	//freopen("F.out", "w", stdout);                                                                                     
	ios_base::sync_with_stdio(NULL);                                                                                
	cin.tie(NULL);
	int n, m;
	cin >> n >> m;
	for (int i = 1; i <= m; i++) {
		int u, v;
		cin >> u >> v;
		u--, v--;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	if (n <= 10) {
		for (int i = 0; i < n; i++) {
			can[(1 << i)][i][i] = 1;
		}
		for (int mask = 1; mask < (1 << n); mask++) {
			for (int s = 0; s < n; s++) {
				if (!(mask >> s & 1)) continue;
				for (int f = 0; f < n; f++) {
					if (!(mask >> f & 1) || f == s) continue;
					for (auto e: adj[f]) {
						if (!(mask >> e & 1)) continue;
						can[mask][s][f] |= can[mask ^ (1 << f)][s][e];
					}
					if (can[mask][s][f]) {
						h[s][f].pb(mask);
					}
				}
			}
		}
		int ans = 0;
		for (int s = 0; s < n; s++) {
			for (int c = 0; c < n; c++) {
				for (int f = 0; f < n; f++) {
					if (f == c || f == s || s == c) continue;
					bool ok = 0;
					for (auto a: h[s][c]) {
						for (auto b: h[c][f]) {
							if ((a & b) == (1 << c)) ok = 1;
							if (ok) break;
						}
						if (ok) break;
					}
					ans += ok;
				}
			}
		}
		cout << ans;
	}else {
		int ans = 0;
		for (int i = 0; i < n; i++) {
			if (!was[i]) {
				v = 0, d = 0;
			 	dfs(i);
			 	d /= 2;
			 	if (v < 3) continue;
			 	if (d == v * 2) ans += v * (v - 1) * (v - 2);
			 	else {     	
			 		for (int j = 1; j <= v - 2; j++) {
			 			ans += (v - j) * (v - j - 1);	
			 		}
				}
			}
		}
		cout << ans;
	}
}

Compilation message (stderr)

count_triplets.cpp:3: warning: ignoring '#pragma optimize ' [-Wunknown-pragmas]
    3 | #pragma optimize ("g",on)
      | 
count_triplets.cpp:9: warning: ignoring '#pragma comment ' [-Wunknown-pragmas]
    9 | #pragma comment(linker, "/stack:200000000")
      | 
count_triplets.cpp:54:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   54 | main() {
      | ^~~~

• Subtask 1: 5 / 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