OI-Codes/FZOI/「NOIP2001」数的划分.cpp

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

int n, k, cnt;

void dfs(int last, int sum, int cur)
{
    if (cur == k)
    {
        if (sum == n)
            cnt++;
        return;
    }
    for (int i = last; sum + i * (k - cur) <= n; i++)
        dfs(i, sum + i, cur + 1);
}

signed main()
{
    cin >> n >> k ;
    dfs(1, 0, 0);
    cout << cnt ;
}