LintCode: A + B Problem

C++

class Solution {
public:
    /*
     * @param a: The first integer
     * @param b: The second integer
     * @return: The sum of a and b
     */
    int aplusb(int a, int b) {
        // write your code here, try to do it without arithmetic operators.
        int sum = a^b;
        int carry = (a&b) << 1;
        int tmp;
        while (carry) {
            tmp = sum;
            sum = tmp^carry;
            carry = (tmp&carry) << 1;
        }
        return sum;
    }
};