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.
Credits:
Special thanks to @ts for adding this problem and creating all test cases.
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c++ code:
class Solution {
public:
int hammingWeight(uint32_t n) {
int count=0;
while(n)
{
if(n & 1) count++;
n >>= 1;
}
return count;
}
};java code:
public class Solution {
// you need to treat n as an unsigned value
public int hammingWeight(int n) {
int cnt = 0;
while(n!=0) {
cnt++;
n &= n-1;
}
return cnt;
}
}原文：http://blog.csdn.net/itismelzp/article/details/51378020