Using a combination of HTML/PHP, implement a web page where the users can upload a text file, exclusively in .txt format, which contains a string of 400 numbers, such as:
computer science
Description
Using a combination of HTML/PHP, implement a web page where the users can upload a text file, exclusively in .txt format, which contains a string of 400 numbers, such as:
71636269561882670428
85861560789112949495
65727333001053367881
52584907711670556013
53697817977846174064
83972241375657056057
82166370484403199890
96983520312774506326
12540698747158523863
66896648950445244523
05886116467109405077
16427171479924442928
17866458359124566529
24219022671055626321
07198403850962455444
84580156166097919133
62229893423380308135
73167176531330624919
30358907296290491560
70172427121883998797
Your code should contain a PHP function that, accepting the string of 400 numbers in input, is able to find the greatest product of four adjacent numbers in all the four possible directions (up, down, left, right, or diagonally).
NOTE:
- You will need to arrange the numbers in a grid 20x20.
- If the file doesn't contain 400 numbers or contains some characters in between, it should be discarded and the application should inform the user that the file is not format correctly.
- You can ignore new lines and white spaces.
- Add a tester function to check the behavior of your PHP function.
- Follow the guidelines discussed and showed in class to avoid losing points.
