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371. Sum of Two Integers

Description

Given two integers a and b, return the sum of the two integers without using the operators + and -.

 

Example 1:

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

Example 2:

Input: a = 2, b = 3
Output: 5

 

Constraints:

  • -1000 <= a, b <= 1000

Solutions

Solution 1

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class Solution:
    def getSum(self, a: int, b: int) -> int:
        a, b = a & 0xFFFFFFFF, b & 0xFFFFFFFF
        while b:
            carry = ((a & b) << 1) & 0xFFFFFFFF
            a, b = a ^ b, carry
        return a if a < 0x80000000 else ~(a ^ 0xFFFFFFFF)

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class Solution {
    public int getSum(int a, int b) {
        return b == 0 ? a : getSum(a ^ b, (a & b) << 1);
    }
}

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class Solution {
public:
    int getSum(int a, int b) {
        while (b) {
            unsigned int carry = (unsigned int) (a & b) << 1;
            a = a ^ b;
            b = carry;
        }
        return a;
    }
};

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func getSum(a int, b int) int {
    for b != 0 {
        s := a ^ b
        b = (a & b) << 1
        a = s
    }
    return a
}

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