A + B Problem

Write a function that add two numbers A and B. You should not use + or any arithmetic operators.

分析：

典型的Bit Operation.

 class Solution {
     /*
      * param a: The first integer
      * param b: The second integer
      * return: The sum of a and b
      */
     public int aplusb(int a, int b) {
         if (a == ) return b;
         int sum = a ^ b;
         int carry = (a & b) << ;
         return aplusb(carry, sum);
     }
 };