Java源碼 Integer.bitCount實(shí)現(xiàn)過(guò)程

//leetcode 461 高票解法
public class Solution {
    public int hammingDistance(int x, int y) {
        return Integer.bitCount(x ^ y);
    }
}

//計(jì)算二進(jìn)制中1的個(gè)數(shù)
class Solution {
    public int hammingDistance(int x, int y) {
        int diff = x ^ y; //xor for the difference of x and y，same=0，diff=1
        return countOne(diff);
    }
    
    private int countOne(int num){
        int count = 0;
        while(num != 0){
            num = num & (num - 1);
            count++;
        }
        return count;
    }
}