bzoj1621 / P2907 [USACO08OPEN]农场周围的道路Roads Around The Farm

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #define re register
 5 using namespace std;
 6 int n,k,ans;
 7 void dfs(int x){
 8     if(x<=k||((x-k)&1)){//不能有半只奶牛（大雾）
 9         ++ans; return;
10     }dfs((x-k)/2); dfs((x-k)/2+k);//分成2群
11 }
12 int main(){
13     scanf("%d%d",&n,&k);dfs(n);
14     printf("%d",ans);
15     return 0;
16 }