树形递归——1621: [Usaco2008 Open]Roads Around The Farm

想下递归过程

注意位运算优先级小，加括号

View Code

#include<stdio.h>

int k;

int dfs(int left)
{
    if((left-k)<=1||((left-k)%2)==1)
    {
        return 1;
    }
    return dfs((left-k)>>1)+dfs(left-((left-k)>>1));
}

int main()
{
    int n;
    while(scanf("%d%d",&n,&k)!=EOF)
    {
        printf("%d\n",dfs(n));
    }
}