DSA · Theory

Counting Sort Algorithm

Theory

55/810

Counting Sort Algorithm

Counting Sort Algorithm 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 Counting Sort Algorithm.

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

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

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

Exam tip

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

Example

# Counting Sort Algorithm
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)

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

Short notes

DefCounting Sort Algorithm — names A→Z in the roll list.
Rulen log n vs n²
Trapunstable sort when equal keys matter
Usethe roll list

DSA · Theory

Counting Sort Algorithm

← All stacks

Theory

55/810

Counting Sort Algorithm

Counting Sort Algorithm 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 Counting Sort Algorithm.

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

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

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

Exam tip

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

Example

# Counting Sort Algorithm
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)

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

Short notes

DefCounting Sort Algorithm — names A→Z in the roll list.
Rulen log n vs n²
Trapunstable sort when equal keys matter
Usethe roll list

Counting Sort Algorithm

Example

Short notes

Questions

Counting Sort Algorithm

Example

Short notes

Questions