Check if two numbers are equal without using arithmetic and comparison operators

Given two numbers, the task is to check if two numbers are equal without using Arithmetic and Comparison Operators or String functions.

Method 1 : The idea is to use XOR operator. XOR of two numbers is 0 if the numbers are the same, otherwise non-zero. 

Not Same

Time Complexity: O(1)
Auxiliary Space: O(1)

Method 2 : Here idea is using complement ( ~ ) and bit-wise '&' operator. 

Not Same

Time Complexity: O(1)
Auxiliary Space: O(1)

Using bit manipulation:

Approach:

Another approach is to use bit manipulation to compare each bit of the two numbers. We can use the bit-shift operators to extract each bit and compare them one by one.

• Define a function named is_equal that takes two arguments num1 and num2.
• Initialize a variable mask to 1.
• Loop through the range of 32 bits (assuming 32-bit integers).
• Use the bitwise AND operator (&) to extract the i-th bit of num1 and num2.
• Compare the extracted bits using the not equal to operator (!=).
• If the extracted bits are not equal, return False.
• Shift the mask left by one bit using the left shift operator (<<).
• Return True if all bits are equal.

True
False

Time complexity: O(log n)
Space complexity: O(1)

Source: https://www.geeksforgeeks.org/dsa/count-of-n-digit-numbers-whose-sum-of-digits-equals-to-given-sum/