递推 + 前缀和

解题思路:
递推 + 前缀和

注意事项:

参考代码:

#include <iostream>

#include <cstring>

#include <algorithm>

using namespace std;

const int N = 100010, mod = 5000011;

int n, m;

int f[N], s[N];

int main(){

cin >> n >> m;

f[0] = 1, s[0] = 1;

for(int i = 1; i <= n; i ++ ) // 

{

if(i - m - 1 < 0) f[i] = 1;

else f[i] = s[i - m - 1];

s[i] = (s[i - 1] + f[i]) % mod;

}

cout << s[n];

return 0;

}