Task: Matrix multiplication

Create a Laravel / Lumen application for Matrix multiplication. The app should feature a Rest-API with authentication.

Validation

For Matrix multiplication, the column count in the first matrix should be equal to the row count of the second matrix. If this condition is not met, the app should throw a validation error.

resulting matrix

The resulting matrix should contain characters rather than numbers, similar to excel columns. Examples: 1 => A, 26 => Z, 27 => AA, 28 => AB. At leat the calculation should be covered by tests.

Technical Details

• At least PHP 7.2 for coding
• PSR-2 coding standard
• strict type hinting

How to call the API

• post request
• URL/API: "/matrixmulti"
• API-key: key=XOzTd4KJOq
• two matrices: data={"m1":[[2,3],[7,4]],"m2":[[1,4],[3,6]]}
• example request body: data={"m1":[[2,3],[7,4],[1,6]],"m2":[[1,4,123],[3,6,14]] }&key=XOzTd4KJOq

Visual Test

• I wrote a visual test with two matrices
• You can call the test via "/matrixmulti/test" with a get request

Tech Stack

• Laravel Lumen
• PHP7
• Visual Studio Code
• PostMan https://www.getpostman.com/
• GIT
• tested the matrix calc with: https://matrixcalc.org/