Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).
For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011
, so the function should return 3.
判断一个数的二进制有几个1
C++(3ms):
1 class Solution { 2 public: 3 int hammingWeight(uint32_t n) { 4 int res = 0 ; 5 while(n){ 6 n = n&(n-1) ; 7 res++ ; 8 } 9 return res ; 10 } 11 };
java(3ms):
1 public class Solution { 2 // you need to treat n as an unsigned value 3 public int hammingWeight(int n) { 4 int res = 0 ; 5 while(n!=0){ 6 n = n&(n-1) ; 7 res++ ; 8 } 9 return res ; 10 } 11 }