371. Sum of Two Integers （实现二进制全加器）

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.

Example:

Given a = 1 and b = 2, return 3.

public class Solution {
    public int getSum(int a, int b) {
      int temp=1,prev=0,tempA,tempB,tempRes,result = 0;
		for(int i=0;i<32;i++){
			tempA = a&temp;
			tempB = b&temp;
			tempRes = tempA^tempB^prev;
			prev = ((tempA^tempB)&prev|tempA&tempB)<<1;
			result |= tempRes;
			temp<<=1;
		}
		return result;  
    }
}