Submission #1005036

#	Time	Username	Problem	Language	Result	Execution time	Memory
1005036		Muaath_5	Kangaroo (CEOI16_kangaroo)	C++17	6 / 100	2041 ms	2624 KiB

kangaroo

#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
using namespace std;

const int N = 2e5+1;

int n, cs, cf;

int main()
{
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	cin >> n >> cs >> cf;
	// sol <= (n-2)!
	vector<int> p(n);
	iota(p.begin(), p.end(), 1);
	int sol = 0;
	do {
		if (p[0] != cs || p[n-1] != cf) continue;
		int f = p[0] < p[1];
		cerr << p[0];
		for (int i = 1; i < n; i++) {
			cerr << p[i];
			if (f && p[i-1] > p[i]) {f = -1; break;}
			if (!f && p[i-1] < p[i]) {f = -1; break;}
			f = !f;
		}
		cerr << endl;
		if (f != -1) sol++;
	} while (next_permutation(p.begin(), p.end()));
	cout << sol;
}

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