Submission #899137

#	Time	Username	Problem	Language	Result	Execution time	Memory
899137		penguin133	Kangaroo (CEOI16_kangaroo)	C++17	6 / 100	2076 ms	348 KiB

kangaroo

#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 ans = 0, P[10];

void solve(){
	int n, x, y; cin >> n >> x>> y;
	for(int i=1;i<=n;i++)P[i] = i;
	do{
		bool f = 1;
		if(P[1] != x || P[n] != y)f = 0;
		if(!f)continue;
		int st = -1;
		for(int i=2;i<=n;i++){
			int sg = (P[i] > P[i-1]);
			if(st == -1)st = sg;
			else if(st == sg)f = 0;
			st = sg;
		}
		if(f)ans++;
	}while(next_permutation(P + 1, P + n + 1));
	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)

kangaroo.cpp:35:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   35 | main(){
      | ^~~~

• Subtask 1: 6 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49