DSA · Theory

Merge K Sorted Linked Lists using Min Heap

Theory

519/810

Merge K Sorted Linked Lists using Min Heap

Merge K Sorted Linked Lists using Min Heap is a DSA topic. In plain words you use it for a ticket queue node in a counter. Don’t start with a slogan — start with that picture.

Smallest example: head → next → …. Type it, run it, and say what you see. If you can do that from memory, you know Merge K Sorted Linked Lists using Min Heap.

From the example next to this theory: Merge K Sorted Linked Lists using Min Heap — heap sort uses a binary heap to repeatedly extract the minimum.

Trap — losing the next pointer on delete. Fix that before you talk about advanced DSA.

Viva — what is Merge K Sorted Linked Lists using Min Heap? Then show head → next → …. Then name the trap.

Diagram

  [10] → [20] → [30] → /
   head              tail

Exam tip

What is Merge K Sorted Linked Lists using Min Heap? Show this: head → next → …. Trap: losing the next pointer on delete.

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]))

Merge K Sorted Linked Lists using Min Heap — heap sort uses a binary heap to repeatedly extract the minimum.

Short notes

DefMerge K Sorted Linked Lists using Min Heap — a ticket queue node in a counter.
Rulehead → next → …
Traplosing the next pointer on delete
Usea counter

DSA · Theory

Merge K Sorted Linked Lists using Min Heap

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Theory

519/810

Merge K Sorted Linked Lists using Min Heap

Merge K Sorted Linked Lists using Min Heap is a DSA topic. In plain words you use it for a ticket queue node in a counter. Don’t start with a slogan — start with that picture.

Smallest example: head → next → …. Type it, run it, and say what you see. If you can do that from memory, you know Merge K Sorted Linked Lists using Min Heap.

From the example next to this theory: Merge K Sorted Linked Lists using Min Heap — heap sort uses a binary heap to repeatedly extract the minimum.

Trap — losing the next pointer on delete. Fix that before you talk about advanced DSA.

Viva — what is Merge K Sorted Linked Lists using Min Heap? Then show head → next → …. Then name the trap.

Diagram

  [10] → [20] → [30] → /
   head              tail

Exam tip

What is Merge K Sorted Linked Lists using Min Heap? Show this: head → next → …. Trap: losing the next pointer on delete.

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]))

Merge K Sorted Linked Lists using Min Heap — heap sort uses a binary heap to repeatedly extract the minimum.

Short notes

DefMerge K Sorted Linked Lists using Min Heap — a ticket queue node in a counter.
Rulehead → next → …
Traplosing the next pointer on delete
Usea counter

Merge K Sorted Linked Lists using Min Heap

Example

Short notes

Questions

Merge K Sorted Linked Lists using Min Heap

Example

Short notes

Questions