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.public class Solution { // you need to treat n as an unsigned value public int hammingWeight(int i) { i = i - ((i >> 1) & 0x55555555); i = (i & 0x33333333) + ((i >> 2) & 0x33333333); return (((i + (i >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24; } }
I do have an easier approach, apparently LeetCode doesn't accept it.
public int hammingWeight(int n) { int ones = 0; while(n > 0){ if((n & 1) > 0) ones++; n = (n >> 1); } return ones; }
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