Search⌘ K
AI Features
Home
Courses
Grokking the Coding Interview Patterns

Solution: Complement of Base 10 Integer

Explore solving the complement of a base 10 integer by understanding how to apply bitwise XOR operations effectively. Learn to calculate the number of bits, create a bitmask, and flip bits to convert binary complements back to decimal efficiently. This lesson ensures you can implement an optimized O(1) time complexity solution for coding interviews involving bitwise manipulation.

We'll cover the following...

Statement

For any nn number in base 10, return the complement of its binary representation as an integer in base 10.

Constraints

  • 0≤n≤1090 \leq n \leq 10^9

Solution

So far, you’ve probably brainstormed some approaches and have an idea of how to solve this problem. Let’s explore some of these approaches and figure out which one to follow based on considerations such as time complexity and any implementation constraints.

Naive approach

To calculate the complement of any integer, we need to perform the following steps:

  1. Convert the integer to its binary value.

  2. Once we have the binary value, we can use a loop to incrementally convert each 11 to 00 and each 00 to 11.

  3. Now that we have the complemented binary number, we can convert it to its ...