DSA · Theory

Cocktail Sort

Theory

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Cocktail Sort is a DSA topic. In plain words you use it for names A→Z in the roll list. Don’t start with a slogan — start with that picture.

Smallest example: n log n vs n². Type it, run it, and say what you see. If you can do that from memory, you know Cocktail Sort.

From the example next to this theory — Cocktail Sort: dry-run [4, 1, 3].

Trap — unstable sort when equal keys matter. Fix that before you talk about advanced DSA.

Viva — what is Cocktail Sort? Then show n log n vs n². Then name the trap.

Exam tip

What is Cocktail Sort? Show this: n log n vs n². Trap: unstable sort when equal keys matter.

# Cocktail Sort
data = [4, 1, 3]
print("start", data)
if data[0] > data[1]:
    data[0], data[1] = data[1], data[0]
print("after one step", data)

Cocktail Sort: dry-run [4, 1, 3]. Say the list after one step.