Flip Bits

Determine the number of bits required to flip if you want to convert integer n to integer m.

 Notice

Both n and m are 32-bit integers.

Example

Given n = 31 (11111), m = 14 (01110), return 2.

class Solution {
    /**
     *@param a, b: Two integer
     *return: An integer
     */
    public static int bitSwapRequired(int a, int b) {
        // write your code here
        int diff = a ^ b;
        int count = 0;
        while (diff != 0) {
            count++;
            // remove the last 1
            diff = diff & (diff - 1);  // 这种方法很好。
        }
        return count;
    }
};