Number of 1 Bits
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.
思路:
1).n&1判断n是最后一位是否为1,是的话,num+1.之后再右移一位。
2).重复1). 直到n变为0
class Solution {
public:
int hammingWeight(uint32_t n) {
int num=0;
while(n>0){
if(n&1==1){
num++;
}
n>>=1;
}
return num;
}
};