12. Number Complement
作者:互联网
Title:
Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.
Example 1:
Input: 5 Output: 2 Explanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.
Example 2:
Input: 1 Output: 0 Explanation: The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.
Note:
- The given integer is guaranteed to fit within the range of a 32-bit signed integer.
- You could assume no leading zero bit in the integer’s binary representation.
Analysis of Title:
Flip the bits of its binary representation.
Python:
return num^(2**(len(bin(num))-2)-1)
Analysis of Code:
Let's solve it down to up.
return b1 ^ b1
return b10 ^ b11
return b11 ^ b11
...
So
...
return num ^ 1,3,7....2**len(num)-1
Notice : When I first to solve it, I want to num ^ 1,11,111,1111....
But actually num is bin and 1,11,... is dec.
标签:binary,12,return,Complement,Number,num,integer,representation,its 来源: https://www.cnblogs.com/sxuer/p/10664113.html