Prove safety offer11: An integer that indicates the number of the output of the binary number 1 in. Wherein a negative number indicates a complement. (Binary conversion, anti-complement code)

1. Title Description

　　An integer that indicates the number of the output of the binary number 1 in. Wherein a negative number indicates a complement.

2. The ideas and methods

　　Use Shift (<<) and "|! &" Operation to achieve. Binary 1 is: 0 in front of all, the last one. Every time it shifted to the left, so that the binary representation of the flag is always only one bit is 1, and each n do bits and operation, this is equivalent to individually detect whether each bit of n is 1. unsigned int flag = 1;

3. C ++ core code

3.1 computing

 1 class Solution {
 2 public:
 3      int  NumberOf1(int n) {
 4          int result = 0;
 5          unsigned int flag = 1;
 6          while(flag)
 7          {
 8              if(n&flag)
 9                  result++;
10              flag = flag<<1;
11          }
12          return result;
13      }
14 };

View Code

 

Reference material

https://blog.csdn.net/qq_28632639/article/details/87966115