【dfs题解】---只有50分

(头一回自己用dfs做出来了dp的hard等级的大题，从来没有拿50分这么高兴过哈哈哈哈哈)

#include <bits/stdc++.h>
using namespace std;
int n,m;
long long ans=0;
const long long mol=1e9+7;
void dfs(int h,int d,int sum)
{if(h<0||d<0||sum<=0)return;if(h==0&&d==0&&sum==2){ans++;ans%=mol;return;}if(sum%2!=0){dfs(h-1,d,sum+1);}else{dfs(h-1,d,sum+1);dfs(h,d-1,sum/2);}
}int main()
{scanf("%d%d",&n,&m);dfs(m-2,n,2);printf("%d",ans);return 0;
}

dp题解等赛后再补上