Sum of Two Integers(leetcode317)

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

Example 1:

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

Example 2:

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

 

//不能使用 + -
public static int getSum(int a, int b) {

    return b==0? a:getSum(a^b, (a&b)<<1);
}

public static int getSum2(int a, int b) {
    if (a == 0) {
        return b;
    }
    if (b == 0) {
        return a;
    }

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

git：https://github.com/woshiyexinjie/leetcode-xin