L1 A plus B

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

Notice

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

Clarification

Are a and b both32-bitintegers?

• Yes.

Can I use bit operation?

• Sure you can.

Example

Givena=1andb=2return3

Challenge

Of course you can just return a + b to get accepted. But Can you challenge not do it like that?

public int aplusb(int a, int b) {
    if (a == 0 && b == 0) {
        return 0;
    } else if (a == 0 && b != 0) {
        return b;
    } else if (a != 0 && b == 0) {
        return a;
    }

    while (b != 0) {
        int sum = a ^ b;
        int carry = (a & b) << 1;
        a = sum;
        b = carry;
    }

    return a;
}