AC了，但是有大大的疑问

#include <bits/stdc++.h>
using namespace std;
const int MOD = 100003;
const int MAXN = 100000 + 5;
int n, k;
int f[MAXN];
void Debug() {
	for (int i = 1; i <= n; i ++) {
		cout << "台阶: " << i << " 方案数：" << f[i] << '\n';
	}
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cin >> n >> k;
    f[1] = 1;
    for (int i = 2; i <= n + 1; i ++) {
    	for (int j = 1; j <= k; j ++) {
			if (i - j >= 0) {
				f[i] = (f[i] + f[i - j]) % MOD;
			} else {
				break;
			}
		}
	}
	//Debug();
	cout << f[n + 1] << '\n';
	return 0;
}