Generate 10 000 unique 4-size arrays whose sum equals 100 000 f# [duplicate]

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• random generation into fsharp list 3 answers

I have piece of code that should generate 10000 4-size arrays whose sum is 100000. but once it generates the first array the others are the same. And I have no idea why.

let mutable sum = 0 let mutable temp = 0

let test: int [] [] = Array.init 10000 (fun _ ->
                                              sum <- 0
                                              temp <- 0
                                              let test = Array.init 4 (fun i ->  
                                                                                if not (i = 4) then
                                                                                    let y = System.Random()
                                                                                    temp <- y.Next((100000 - sum) / (4 - i)) + 1
                                                                                    sum <- sum + temp
                                                                                    temp
                                                                                else
                                                                                let mutable k = 100000 - sum
                                                                                sum <- sum + temp
                                                                                k)
                                              test)