What is Binary Search Algorithm?

What is Binary Search Algorithm?

Imagine you have a long list of items arranged in order, like numbers from 1 to 100. You want to find a specific number, let’s say 42, in the fastest way possible. Binary search is like a clever way of finding it without checking each number one by one.

Here’s how Binary Search Algorithm works:

1. Start in the Middle:
   • You don’t start from the beginning or the end; you start right in the middle of the list.
   • In our example, the middle is 50 (halfway between 1 and 100).
2. Is it the Number?
   • You check if the number you’re looking for (42) is equal to the middle number (50).
   • If yes, you found it!
3. Narrow Down the Search:
   • If 42 is smaller than 50, you now focus on the first half of the list (1 to 49).
   • If 42 is larger than 50, you focus on the second half (51 to 100).
4. Repeat the Process:
   • Now, you repeat the process. Start in the middle of the narrowed-down list.
   • If the middle number is 30, and you’re looking for 42, you know to focus on the right half (31 to 49).
5. Keep Going Until You Find It:
   • You keep splitting and narrowing down until you find the number you’re looking for.

Example of Binary Search Algorithm:

Let’s see how it works step by step:

1. Start with the whole list: 1 to 100.
2. Middle is 50. Is it 42? No. Since 42 is smaller, focus on the first half (1 to 49).
3. Middle is 25. Is it 42? No. Since 42 is larger, focus on the second half (26 to 49).
4. Middle is 37. Is it 42? No. Focus on the second half again (38 to 49).
5. Middle is 43. Is it 42? Yes! You found it.

Binary search helps you find the right item much faster than checking each one individually. It’s like playing a guessing game, getting closer with each guess until you hit the bullseye.