C# Standard Array[ ] Randomiser Code Snippet

General information for the business: R&D
Kind of development: New program from scratch
Description of requirements/functionality: you have a C# byte[] ArrayA[0 to Arraysize -1]

NOW write a C# code snippet to randomise/shuffle above Array ( do not write/ make into a function , just write code statements will do )

THEN write the unshuffle/ derandomise code statements , get back original unshuffled ArrayA

[ THE RANDOMISER / DERANDOMISER SHOULD PREFERABLE USE SIMPLE FISHER-YATES SWAPPING ARRAY ELEMENTS , BASED ON A RANDOM KEY VALUE SPECIFIED ( int key = eg 1234 ) ]

should take only couple hours

simple DOS box will do
Extra notes:

write DOS box C# read in from ASCII 0 1 input.txt ( variable lengths ArraySize) into ArrayA[ 0 to ArraySize]

THEN shuffle/randomise ArrayA[ ] , write shuffled ArrayA[ ] to Shuffled.txt ( ASCII 0 1 )

Then read in from Shuffled.txt into ArrayB[ 0 to ArraySize], unshuffle ArrayB back into original unshuffled Array

THATS ALL
yes DOS console , input /output files in ASCII 0 1 .txt ( variable length )

you may start Fisher-Yates by filling in Array Exchange[i] with random generated # between 0 to i , this random # 0 to i generated randomly ( using based on seed value specified , ie int key = eg 1234 etc ... so that you can subsequent reverse/unshuffle shuffled Array back to original Array again using same key value eg 1234 etc specified )

can you complete in few hours ?