Lähetit

#include <iostream>

long t[2][202][202];

int main() {
	int n, k;
	std::cin >> n >> k;
	for (int l = 0; l <= 1; ++l) {
		for (int i = 0; i < n; ++i) {
			int leveys = (i & ~1) + (l ? 1 : 2);
			for (int j = 0; j <= k && j <= leveys; ++j) {
				if (i) {
					// ei uutta
					t[l][i][j] = t[l][i-1][j];
					// uusi edellisten lisäksi
					if (j) {
						t[l][i][j] = (t[l][i][j] + t[l][i-1][j-1] * (leveys - (j-1))) % 1000000007;
					}
				} else {
					// ensimmäisellä rivillä
					// - yksi mihin tahansa (leveys)
					// - monta ei mitenkään (0)
					// - tyhjä rivi yhdellä tavalla (1)
					t[l][i][j] = j ? j > 1 ? 0 : leveys : 1;
				}
			}
		}
	}
	long ret = 0;
	for (int i = 0; i <= k && i <= n; ++i) {
		ret += (t[1][n-1][i] * t[0][n-2][k-i]) % 1000000007;
	}
	std::cout << (ret % 1000000007) << '\n';
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED