1. binary search

What is linear search?

A search method that checks each item one by one from start to end.

What is binary search?

A fast search that repeatedly checks the middle of a sorted list.

What kind of list does binary search require?

A sorted list (numbers or items must be in order).

What are the starting values of low and high in binary search?

low = 0, high = len(list) - 1

How do you find the middle index in binary search?

mid = (low + high) // 2

When does binary search stop?

When the target is found, or when low > high.

What does binary search return if it finds the item?

The index of the item.

What does binary search return if it doesn't find the item?

None (or -1, depending on the code).

What is the time complexity of linear search?

O(n) — slower for large lists.

What is the time complexity of binary search?

O(log n) — much faster than linear for big lists.

What does log₂(n) tell you in binary search?

How many times you can cut the list in half before it's empty.

Binary vs. Linear Search: which is faster for large lists?

Binary search — but only if the list is sorted.

Why does binary search fail on unsorted lists?

Because the logic assumes sorted order to skip parts of the list.