See the test suite of http://www.mathworks.co.uk/matlabcentral/cody/problems/2513 for an example of how to make sure regexp and other functions are not used.
Thanks for the tip, modified the test suite and updated the problem description to include regexpi in the list of illegal functions.
Modified the test suite again, sorry if it affects your solution.
Summing Digits within Text
Replace multiples of 5 with NaN
Reverse a matrix
Vectors counting by 2
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Contact your local office