Convert Integer A to Integer B

Convert Integer A to Integer B

Determine the number of bits required to convert integer A to integer B 

Example

Given n = 31, m = 14,return 2

(31)10=(11111)2

(14)10=(01110)2

--------------- codes ---------------------------
class Solution {
public:
    /**
     *@param a, b: Two integer
     *return: An integer
     */
    int bitSwapRequired(int a, int b) {
        // write your code here
        //bug here: remember to consider sing of a and b
        unsigned int a_or_b = (unsigned int)a^(unsigned int)b;
        int cnt = 0;
        while (a_or_b) {
            cnt += a_or_b&1;
            a_or_b = a_or_b >> 1;
        }
        return cnt;
    }
};