Problem Description
long long ans = 0;
for(int i = 1; i <= n; i ++)
ans += lowbit(i)
lowbit(i)的意思是将i转化成二进制数之后，只保留最低位的1及其后面的0，截断前面的内容，然后再转成10进制数
比如lowbit(7),7的二进制位是111，lowbit(7) = 1
6 = 110(2),lowbit(6) = 2,同理lowbit(4) = 4,lowbit(12) = 4,lowbit(2) = 2,lowbit(8) = 8
每输入一个n，求ans
Input
多组数据，每组数据一个n(1 <= n <= 10^9)
Output
每组数据输出一行，对应的ans
Sample Input
1 2 3
Sample Output
1 3 4
1 #include <iostream> 2 #include <stdio.h> 3 #include <string.h> 4 #include <math.h> 5 #include <algorithm> 6 using namespace std; 7 #define ll long long 8 ll solve(int x) 9 { 10 if(x==0)return 0; 11 return ((x+1)>>1)+(solve(x/2)<<1); 12 } 13 int main() 14 { 15 int n; 16 while(~scanf("%d",&n)) 17 { 18 printf("%lld\n",solve(n)); 19 } 20 }
