DSA · Theory

LEFTIST TREE / LEFTIST HEAP

Theory

485/810

LEFTIST TREE / LEFTIST HEAP

LEFTIST TREE / LEFTIST HEAP 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 LEFTIST TREE / LEFTIST HEAP.

From the example next to this theory: LEFTIST TREE / LEFTIST HEAP — heap sort uses a binary heap to repeatedly extract the minimum.

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

Viva — what is LEFTIST TREE / LEFTIST HEAP? Then show left < root < right. Then name the trap.

Exam tip

What is LEFTIST TREE / LEFTIST HEAP? Show this: left < root < right. Trap: unbalanced BST becoming a list.

Example

import heapq

def heap_sort(arr):
    h = arr[:]
    heapq.heapify(h)
    return [heapq.heappop(h) for _ in range(len(h))]

print(heap_sort([5, 1, 4, 2]))

LEFTIST TREE / LEFTIST HEAP — heap sort uses a binary heap to repeatedly extract the minimum.

Short notes

DefLEFTIST TREE / LEFTIST HEAP — folder on disk in a file explorer.
Ruleleft < root < right
Trapunbalanced BST becoming a list
Usea file explorer

DSA · Theory

LEFTIST TREE / LEFTIST HEAP

← All stacks

Theory

485/810

LEFTIST TREE / LEFTIST HEAP

LEFTIST TREE / LEFTIST HEAP 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 LEFTIST TREE / LEFTIST HEAP.

From the example next to this theory: LEFTIST TREE / LEFTIST HEAP — heap sort uses a binary heap to repeatedly extract the minimum.

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

Viva — what is LEFTIST TREE / LEFTIST HEAP? Then show left < root < right. Then name the trap.

Exam tip

What is LEFTIST TREE / LEFTIST HEAP? Show this: left < root < right. Trap: unbalanced BST becoming a list.

Example

import heapq

def heap_sort(arr):
    h = arr[:]
    heapq.heapify(h)
    return [heapq.heappop(h) for _ in range(len(h))]

print(heap_sort([5, 1, 4, 2]))

LEFTIST TREE / LEFTIST HEAP — heap sort uses a binary heap to repeatedly extract the minimum.

Short notes

DefLEFTIST TREE / LEFTIST HEAP — folder on disk in a file explorer.
Ruleleft < root < right
Trapunbalanced BST becoming a list
Usea file explorer

LEFTIST TREE / LEFTIST HEAP

Example

Short notes

Questions

LEFTIST TREE / LEFTIST HEAP

Example

Short notes

Questions