Submission #978985

#	Time	Username	Problem	Language	Result	Execution time	Memory
978985		penguin133	Group Photo (JOI21_ho_t3)	C++17	5 / 100	5005 ms	604 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, A[5005], P[5005], pos[5005];

void solve(){
	cin >> n;
	for(int i = 1; i <= n; i++)cin >> A[i], pos[A[i]] = i;
	int ans = 1e18;
	for(int i = 1; i <= n; i++)P[i] = i;
	do{
		bool f = 1;
		for(int i = 2; i <= n; i++)if(P[i - 1] >= P[i] + 2)f = 0;
		if(!f)continue;
		int cnt = 0;
		for(int i = 1; i <= n; i++){
			for(int j = i + 1; j <= n; j++){
				if(pos[P[i]] > pos[P[j]])cnt++;
			}
		}
		ans = min(ans, cnt);
	}while(next_permutation(P + 1, P + 1 + n));
	cout << ans;
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	for(int tc1=1;tc1<=tc;tc1++){
		// cout << "Case #" << tc1 << ": ";
		solve();
	}
}

Compilation message (stderr)

Main.cpp:36:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   36 | main(){
      | ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 32
• Subtask 4: 0 / 20
• Subtask 5: 0 / 36