DSA · Theory

Total Number of Possible Binary Search Trees with n Keys

Theory

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Total Number of Possible Binary Search Trees with n Keys

Total Number of Possible Binary Search Trees with n Keys is simple if you keep it on paper. Asha uses it for folder on disk in a file explorer.

For Total Number of Possible Binary Search Trees with n Keys, time vs memory is in play. Don’t blame it until you have traced folder on disk.

Without Total Number of Possible Binary Search Trees with n Keys, a file explorer gets messy and folder on disk is hard to trust.

Total Number of Possible Binary Search Trees with n Keys shows up in a file explorer. Name folder on disk, not “a real-world scenario”.

Total Number of Possible Binary Search Trees with n Keys miss: unbalanced BST becoming a list. Fix it before you talk about advanced DSA.

Total Number of Possible Binary Search Trees with n Keys is not a lonely heading. Asha ties it to folder on disk.

Close Total Number of Possible Binary Search Trees with n Keys with: “If I skip it, folder on disk goes wrong like this: unbalanced BST becoming a list.”

Diagram

Exam tip

Say Total Number of Possible Binary Search Trees with n Keys 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))

Total Number of Possible Binary Search Trees with n Keys — binary search halves a sorted array each step — O(log n).

Short notes

DefTotal Number of Possible Binary Search Trees with n Keys — Asha uses it for folder on disk in a file explorer.
RuleTotal Number of Possible Binary Search Trees with n Keys → left < root < right.
RememberTotal Number of Possible Binary Search Trees with n Keys + time vs memory (a file explorer).
UseTotal Number of Possible Binary Search Trees with n Keys in a file explorer (folder on disk).
TrapTotal Number of Possible Binary Search Trees with n Keys — unbalanced BST becoming a list.
ExTotal Number of Possible Binary Search Trees with n Keys → 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))

Total Number of Possible Binary Search Trees with n Keys

Example

Short notes

Questions

Total Number of Possible Binary Search Trees with n Keys

Example

Short notes

Questions