P1025

https://www.luogu.org/problemnew/show/P1025
dfs：

#include <iostream>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <queue>
#include <deque>
#include <stack>

#define INF 0x3f3f3f3
using namespace std;
typedef long long LL;
int N,k,ans;
void dfs(int last,int sum,int cnt)
{
    if(cnt==k)
    {
        if(sum==N)ans++;
        return ;
    }
    for(int i=last;sum+(k-cnt)*i<=N;i++)
        dfs(i,sum+i,cnt+1);
}
int main()
{
    scanf("%d%d",&N,&k);
    dfs(1,0,0);
    printf("%d\n",ans);
    return 0;
}