Leetcode1 - A + B Problem - Easy

Write a function that add two numbers A and B.

Example

Example 1:
	Input:  a = 1, b = 2
	Output: 3

	Explanation:
	return the result of a + b.

Example 2:
	Input:  a = -1, b = 1
	Output: 0

	Explanation:
	return the result of a + b.

Challenge

Of course you can just return a + b to get accepted. But Can you challenge not do it like that?(You should not use + or any arithmetic operators.)

Clarification

Are a and b both 32-bit integers?

• Yes.

Can I use bit operation?

• Sure you can.

Notice

There is no need to read data from standard input stream. Both parameters are given in function aplusb, you job is to calculate the sum and return it.

 

public int aplusb(int a, int b) {
        while (b != 0){
            int _a = a ^ b;
            int _b = (a & b) << 1;
            a = _a;
            b = _b;
        }
        return a;
    }
}