Sum of Two Integers

Sum of Two Integers is a Medium Data Structures and Algorithms interview problem you can solve, run and submit on Thita.ai. It belongs to the Bit Manipulation Patterns pattern, in the Bitwise XOR - Finding Single/Missing Number subpattern.

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Problem statement

Implement Solution.getSum(a, b) to compute the arithmetic sum of the two integer parameters a and b. Return that sum as a JSON integer.

The implementation must not use the + or - operators anywhere in the addition logic. Use bitwise operations to reproduce the effects of adding binary digits and propagating carries.

Both positive and negative values are valid, including zero. The returned value must be mathematically equal to a + b, even though the forbidden operators cannot be used.

Example 1:

Input: a = 14, b = -6 Output: 8 Explanation: Adding 14 and -6 produces 8. The method must obtain this result without using the forbidden arithmetic operators.

Example 2:

Input: a = -23, b = 7 Output: -16 Explanation: The negative value has greater magnitude, so the sum is -16.

Example 3:

Input: a = 0, b = 19 Output: 19 Explanation: Adding zero leaves the other integer unchanged.

Constraints:

- a is an integer. - b is an integer. - -1000 <= a <= 1000. - -1000 <= b <= 1000. - The + operator must not be used. - The - operator must not be used.

Topics and companies

Topics: Bit Manipulation, Math, Iteration.

How to practise Sum of Two Integers on Thita.ai

Starter code is provided in C#, C++, Go, Java, JavaScript and Python. Your solution runs against 5 test cases for this problem, with the AI coach available for a hint when you are stuck rather than a finished answer. The reference solution runs in O(w), where w is the integer bit width; O(1) for 32-bit integers. time and O(1) space.

Open Sum of Two Integers in the code editor, or read the Sum of Two Integers editorial for a worked solution with its approach and complexity analysis.

Where Sum of Two Integers sits in the DSA pattern sheet

• Bit Manipulation Patterns pattern guide
• Bitwise XOR - Finding Single/Missing Number subpattern
• The full DSA patterns sheet
• All coding practice problems

Problems related to Sum of Two Integers

Other problems that use the same Bitwise XOR - Finding Single/Missing Number and Bit Manipulation Patterns techniques:

• Find the Difference — Easy, same subpattern
• Missing Number — Easy, same subpattern
• Single Number — Easy, same subpattern
• Single Number II — Medium, same subpattern
• Bitwise AND of Numbers Range — Medium, same pattern
• Counting Bits — Easy, same pattern