Selection Sort

Selection Sort

What is Selection Sort?
Selection Sort is a way to arrange a list of numbers (or items) in order. We do this by picking the smallest (or largest) number and placing it in its correct position, step by step.

How does it work?

• Look at the whole list and find the smallest number.
• Put that smallest number in the first position.
• Now, ignore the first number (it’s already sorted) and look at the rest of the list. Find the next smallest number and put it in the second position.
• Keep repeating this until the whole list is sorted.

Step-by-step process:

• Find the smallest number in the list.
• Swap it with the number in the first position.
• Find the next smallest number and swap it with the second position.
• Repeat until everything is sorted.

Example:
List: [7, 3, 8, 4]

• Step 1: Find the smallest number (3). Swap it with the first number (7).
  → [3, 7, 8, 4]
• Step 2: Ignore the first number. Now find the smallest number in the rest (4). Swap it with the second number (7).
  → [3, 4, 8, 7]
• Step 3: Ignore the first two numbers. Find the smallest number in the rest (7). Swap it with the third number (8).
  → [3, 4, 7, 8]

Now the list is sorted!

Key idea:
Find the smallest number, put it in the right spot, and repeat until the list is sorted.