How Fast is Your Code?

Not all code is created equal! Some algorithms solve problems faster than others.

Big O Notation

Big O notation describes how the runtime of an algorithm grows as the input size increases.

• \( O(n) \): Linear — time increases with input.
• \( O(n^2) \): Quadratic — time grows much faster.

Sorting Algorithms

Sorting puts elements in order. Common algorithms include:

• Selection Sort: Finds the smallest element and moves it to the front.
• Insertion Sort: Builds a sorted list one item at a time.

// Simple selection sort
for (int i = 0; i < arr.length - 1; i++) {
  int min = i;
  for (int j = i+1; j < arr.length; j++) {
    if (arr[j] < arr[min]) min = j;
  }
  int temp = arr[i];
  arr[i] = arr[min];
  arr[min] = temp;
}

Why This Matters

Efficient algorithms save time and make programs run smoothly—essential for apps, games, and websites!