Python Coding: Difference Without Subtraction | Dataford Interview Questions

Tech Tammina's low-level validation tools must compute the signed difference between two integers without using Python's subtraction operator. Implement this operation using bitwise logic and two's complement arithmetic.

Return the mathematical value of a - b, but do not use subtraction anywhere in the algorithm. You may use addition, bitwise operators, comparisons, loops, integer methods such as bit_length(), and fixed-width masking. Do not call abs, pow for difference computation, or any library function that directly calculates a difference.

Formal Specification

Implement bitwise_difference(a, b):

Input: two Python integers, a and b, which may be positive, zero, or negative.
Output: an integer equal to the signed difference of a and b.
The implementation must support values whose magnitudes require up to 10,000 bits.
The solution must not use the - operator or convert numbers to strings.

Constraints

-2^10000 <= a, b <= 2^10000
Inputs are valid Python integers
The result must equal the mathematical signed difference
The '-' operator is forbidden in the implementation
String conversion and direct difference helpers are forbidden

Function Signature

def bitwise_difference(a, b):

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