90pts求条

#include <bits/stdc++.h>
#define endl '\n'
#define	int long long

using namespace std;
const int N = 110;
int k, n, m, l;
double dp[N][N];

signed main() {
	cin.tie(nullptr)->sync_with_stdio(false);
	cin >> k >> n >> m >> l;
	dp[1][1] = 1;
	for (int i = 1; i < m; i++)
		for (int j = 1; j < l; j++) {
			dp[i + 1][1] += (k - 1) * dp[i][j];
			if (j + 1 < l) 
				dp[i + 1][j + 1] += dp[i][j];
		}
	double total = 0;
	for (int j = 1; j < l; j++)
		total += dp[m][j];
	total *= k;
	cout << (int)(n * 1.0 / m * log2(total)) << endl;
	return 0;
}