Problem 162. High school cafeteria

Created by the cyclist

Solve Later

Given an input vector of positive integers, return a row vector with the primes first (in increasing order) and the composites next (also in increasing order).

The number 1 is neither prime nor composite. Put it with the composites for this problem.

Solve

Solution Stats

571 Solutions
236 Solvers

Last Solution submitted on Dec 16, 2025

Last 200 Solutions

Problem Comments

4 Comments

4 Comments

Show 1 older comment

Alfonso Nieto-Castanon on 29 Jan 2012

need to add non-sorted test samples (e.g. [3,2,1])?

Tom Holz on 26 Feb 2013

It looks like 1 is being incorrectly sorted as a composite number in the testcases.

the cyclist on 27 Feb 2013

I somehow Alfonso's older comment until I saw Tom's newer one.

Alfonso: I've added a non-sorted test sample, and had the problem rescored.

Tom: 1 is neither prime nor composite. I've added instructions on how to handle that.

Ned Gulley on 20 Jun 2013

I had assumed that "in order" meant "in the order provided". If that were the case, then [5 1 3 2 4] would return [5 3 2 1 4]. Maybe you could say you want them sorted rather than in order.

Solution Comments

Show comments

Problem Recent Solvers236

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 162. High school cafeteria

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers236

Suggested Problems

More from this Author23

Problem Tags

Community Treasure Hunt

Problem 162. High school cafeteria

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers236

Suggested Problems

More from this Author23

Problem Tags

Community Treasure Hunt

Players