Problem 2456. remove single elements

Created by rifat
Appears in Indexing III

Difficulty:Rate

Solve Later
Add To GroupÃ‚

Given a vector of integers, remove the elements that have appeared only once. The output elements should be in exact order as the input except the single elements being removed.
Example:
Input: vec = [2 2 1 2 3 4 1 2];
Output: [2 2 1 2 1 2];
Loops are not allowed.

Solve

Solution Stats

423 Solutions
115 Solvers

Last Solution submitted on Aug 12, 2025

Last 200 Solutions

Problem Comments

4 Comments

4 Comments

Show 1 older comment

shahriar memaran on 25 Mar 2017

Test suit # 4 should not compare out = [] with output of the function but rather isempty(out) !!!

Christian Schröder on 21 Oct 2022

Two requests:

1. Please don't add intentional infinite loops to the test suite.
2. Please take more care when scanning for forbidden keywords. "x(grouptransform(x', x', @numel) > 1)" would be a perfectly good solution, but fails the test suite because "grouptransform" contains the letters "for".

Thanks.

Dyuman Joshi on 22 Oct 2022

Test suite has been updated -

The infinite loop has been cleared out, scanning for 'for' loop has been modified and empty sets will now be verified using isempty().

Solution Comments

Show comments

Problem Recent Solvers115

Problem Tags

Community Treasure Hunt

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

Start Hunting!

Problem 2456. remove single elements

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers115

Suggested Problems

More from this Author44

Problem Tags

Community Treasure Hunt

Problem 2456. remove single elements

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers115

Suggested Problems

More from this Author44

Problem Tags

Community Treasure Hunt

Players