DSA · Theory

What are linear search and binary search

Theory

208/810

What are linear search and binary search

What are linear search and binary search is a DSA topic. In plain words you use it for folder on disk in a file explorer. Don’t start with a slogan — start with that picture.

Smallest example: left < root < right. Type it, run it, and say what you see. If you can do that from memory, you know What are linear search and binary search.

From the example next to this theory: What are linear search and binary search — binary search halves a sorted array each step — O(log n).

Trap — unbalanced BST becoming a list. Fix that before you talk about advanced DSA.

Viva — what is What are linear search and binary search? Then show left < root < right. Then name the trap.

Diagram

  [2, 5, 8, 12, 20]  find 12
         mid=8 → right
              mid=12 found

Exam tip

What is What are linear search and binary search? Show this: left < root < right. Trap: unbalanced BST becoming a list.

Example

def binary_search(arr, target):
    lo, hi = 0, len(arr) - 1
    while lo <= hi:
        mid = (lo + hi) // 2
        if arr[mid] == target:
            return mid
        if arr[mid] < target:
            lo = mid + 1
        else:
            hi = mid - 1
    return -1

print(binary_search([1, 3, 5, 7, 9], 7))

What are linear search and binary search — binary search halves a sorted array each step — O(log n).

Short notes

DefWhat are linear search and binary search — folder on disk in a file explorer.
Ruleleft < root < right
Trapunbalanced BST becoming a list
Usea file explorer

DSA · Theory

What are linear search and binary search

← All stacks

Theory

208/810

What are linear search and binary search

What are linear search and binary search is a DSA topic. In plain words you use it for folder on disk in a file explorer. Don’t start with a slogan — start with that picture.

Smallest example: left < root < right. Type it, run it, and say what you see. If you can do that from memory, you know What are linear search and binary search.

From the example next to this theory: What are linear search and binary search — binary search halves a sorted array each step — O(log n).

Trap — unbalanced BST becoming a list. Fix that before you talk about advanced DSA.

Viva — what is What are linear search and binary search? Then show left < root < right. Then name the trap.

Diagram

  [2, 5, 8, 12, 20]  find 12
         mid=8 → right
              mid=12 found

Exam tip

What is What are linear search and binary search? Show this: left < root < right. Trap: unbalanced BST becoming a list.

Example

def binary_search(arr, target):
    lo, hi = 0, len(arr) - 1
    while lo <= hi:
        mid = (lo + hi) // 2
        if arr[mid] == target:
            return mid
        if arr[mid] < target:
            lo = mid + 1
        else:
            hi = mid - 1
    return -1

print(binary_search([1, 3, 5, 7, 9], 7))

What are linear search and binary search — binary search halves a sorted array each step — O(log n).

Short notes

DefWhat are linear search and binary search — folder on disk in a file explorer.
Ruleleft < root < right
Trapunbalanced BST becoming a list
Usea file explorer

What are linear search and binary search

Example

Short notes

Questions

What are linear search and binary search

Example

Short notes

Questions