hdu 5524 二叉树找规律，二进制相关

input

n 1<=n<=1e18

output

有n个结点的满二叉树有多少个不相同结点数的子树

做法：树有h=log2(n)层，最多有2h-2种(1除外),然后再n减去u重复的即可

 #include <bits/stdc++.h>
 #include <cstdio>
 #include <queue>
 #include <cstring>
 #include <iostream>
 #include <cstdlib>
 #include <algorithm>
 #include <vector>
 #include <map>
 #include <set>
 #include <ctime>
 #include <cmath>
 #include <cctype>
 #include <string>
 #include <bitset>
 #define MAX 100000
 #define LL long long
 using namespace std;
 LL n;
 int highbit(LL x)
 {
     for(int i=;i>=;i--) if(x&(1LL<<i)) return i+;
 }
 int lowbit(LL x)
 {
     for(int i=;i<=;i++) if(x&(1LL<<i)) return i;
 }
 int main()
 {
     freopen("in","r",stdin);
     //scanf("%d",&T);
     while(scanf("%lld",&n)==)
     {
         int h=highbit(n);
         LL maxn=(1LL<<h)-;LL mid=maxn-(1LL<<(h->=?h-:));
 //        printf("%lld:",n);
 //        printf("h=%d maxn=%lld mid=%lld\n",h,maxn,mid);
         if(n==maxn||n==mid) { printf("%d\n",h);continue; }
         h+=h-;
         if(n<=mid) h--;
         h-=lowbit(n-(maxn>>));
         printf("%d\n",h);
     }
     //printf("time=%.3lf",(double)clock()/CLOCKS_PER_SEC);
     return ;
 }