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Optimal Binary Search Tree

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Optimal Binary Search Tree

Optimal Binary Search Tree is simple if you keep it on paper. Isha uses it for folder on disk in a file explorer.

For Optimal Binary Search Tree, time vs memory is in play. Don’t blame it until you have traced folder on disk.

Skip Optimal Binary Search Tree and unbalanced BST becoming a list shows up in a file explorer.

Optimal Binary Search Tree shows up in a file explorer. Name folder on disk, not “a real-world scenario”.

Don’t do this with Optimal Binary Search Tree: unbalanced BST becoming a list. Interviewers spot it in ten seconds.

Optimal Binary Search Tree is not a lonely heading. Isha ties it to folder on disk.

Close Optimal Binary Search Tree with: “If I skip it, folder on disk goes wrong like this: unbalanced BST becoming a list.”

Diagram

Exam tip

Say Optimal Binary Search Tree in one breath, then left < root < right, then 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))

Optimal Binary Search Tree — binary search halves a sorted array each step — O(log n).

Short notes

DefOptimal Binary Search Tree — Isha uses it for folder on disk in a file explorer.
RuleOptimal Binary Search Tree → left < root < right.
RememberOptimal Binary Search Tree + time vs memory (a file explorer).
UseOptimal Binary Search Tree in a file explorer (folder on disk).
TrapOptimal Binary Search Tree — unbalanced BST becoming a list.
ExOptimal Binary Search Tree → folder on disk.

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))

Optimal Binary Search Tree

Example

Short notes

Questions

Optimal Binary Search Tree

Example

Short notes

Questions