Why Check if Number is Even or Odd Using Bits in DSA C?

The Big Idea

Discover how a tiny bit can save you big time in checking numbers!

The Scenario

Imagine you have a long list of numbers and you want to quickly find out which ones are even and which are odd. Doing this by dividing each number by 2 and checking the remainder can be slow if the list is very long.

The Problem

Using division and modulus operations repeatedly takes more time and uses more computing power. It can slow down programs, especially when working with large data or in devices with limited resources.

The Solution

Using bits, you can check if a number is even or odd by looking at just one bit: the last bit. If the last bit is 0, the number is even; if it is 1, the number is odd. This method is very fast and efficient.

Before vs After

✗ Before

if (number % 2 == 0) {
    // even
} else {
    // odd
}

✓ After

if ((number & 1) == 0) {
    // even
} else {
    // odd
}

What It Enables

This lets you quickly and efficiently determine even or odd numbers, speeding up programs and saving resources.

Real Life Example

In games or graphics, quickly checking even or odd numbers can help decide patterns or colors without slowing down the frame rate.

Key Takeaways

Manual division is slower and uses more resources.

Bitwise check uses only one bit to decide even or odd.

This method is faster and better for performance-critical tasks.