07
04/2015
[LeetCode] Number of 1 Bits
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.
解题思路：
对于正整数，n=n&(n-1)表示去除最后一个1。如此计数。下面是代码：
class Solution {
public:
int hammingWeight(uint32_t n) {
int result=0;
while(n!=0){
n=n&(n-1); //这个式子表示去掉n最后一个1
result++;
}
return result;
}
};转载请注明：康瑞部落 » [LeetCode] Number of 1 Bits
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