# Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique

Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Section 3.3 of [Generalised 2-designs with Block Size 3(Andy L. Drizen)] describes a method of generating Latin Squares of order n attributed to Jacobson and Matthews. The purpose of this task is to produce a function which given a valid Latin Square transforms it to another using this method.

part 1

Use one of the 4 Latin Squares in reduced form of order 4 as X0 to generate 10000 Latin Squares using X(n-1) to generate X(n). Convert the resulting Latin Squares to their reduced form, display them and the number of times each is produced.

part 2

As above for order 5, but do not display the squares. Generate the 56 Latin Squares in reduced form of order 5, confirm that all 56 are produced by the Jacobson and Matthews technique and display the number of each produced.

part 3

Generate 750 Latin Squares of order 42 and display the 750th.

part 4

Generate 1000 Latin Squares of order 256. Don't display anything but confirm the approximate time taken and anything else you may find interesting

## F#

### The Functions

` // Jacobson and Matthews technique for generating Latin Squares. Nigel Galloway: August 5th., 2019let R=let N=System.Random() in (fun n->N.Next(n)) let jmLS α X0=  let X0=Array2D.copy X0  let N=let N=[|[0..α-1];[α-1..(-1)..0]|] in (fun()->N.[R 2])  let rec randLS i j z n g s=    X0.[i,g]<-s; X0.[n,j]<-s    if X0.[n,g]=s then X0.[n,g]<-z; X0    else randLS n g s (List.find(fun n->X0.[n,g]=s)(N())) (List.find(fun g->X0.[n,g]=s)(N())) (if (R 2)=0 then let t=X0.[n,g] in X0.[n,g]<-z; t else z)  let i,j=R α,R α  let z  =let z=1+(R (α-1)) in if z<X0.[i,j] then z else 1+(z+1)%α  let n,g,s=let N=[0..α-1] in (List.find(fun n->X0.[n,j]=z) N,List.find(fun n->X0.[i,n]=z) N,X0.[i,j])  X0.[i,j]<-z; randLS i j z n g s let asNormLS α=  let n=Array.init (Array2D.length1 α) (fun n->(α.[n,0]-1,n))|>Map.ofArray  let g=Array.init (Array2D.length1 α) (fun g->(α.[n.[0],g]-1,g))|>Map.ofArray  Array2D.init (Array2D.length1 α) (Array2D.length1 α) (fun i j->α.[n.[i],g.[j]]) let randLS α=Seq.unfold(fun g->Some(g,jmLS α g))(Array2D.init α α (fun n g->1+(n+g)%α)) `

part 1
` randLS 4 |> Seq.take 10000 |> Seq.map asNormLS |> Seq.countBy id |> Seq.iter(fun n->printf "%A was produced %d times\n\n" (fst n)(snd n)) `
Output:
```[[1; 2; 3; 4]
[2; 3; 4; 1]
[3; 4; 1; 2]
[4; 1; 2; 3]] was produced 2920 times

[[1; 2; 3; 4]
[2; 4; 1; 3]
[3; 1; 4; 2]
[4; 3; 2; 1]] was produced 2262 times

[[1; 2; 3; 4]
[2; 1; 4; 3]
[3; 4; 2; 1]
[4; 3; 1; 2]] was produced 2236 times

[[1; 2; 3; 4]
[2; 1; 4; 3]
[3; 4; 1; 2]
[4; 3; 2; 1]] was produced 2582 times
```
part 2
` randLS 5 |> Seq.take 10000 |> Seq.map asNormLS |> Seq.countBy id |> Seq.iteri(fun n g->printf "%d(%d) " (n+1) (snd g)); printfn "" `
Output:
```1(176) 2(171) 3(174) 4(165) 5(168) 6(182) 7(138) 8(205) 9(165) 10(174) 11(157) 12(187) 13(181) 14(211) 15(184) 16(190) 17(190) 18(192) 19(146) 20(200) 21(162) 22(153) 23(193) 24(156) 25(148) 26(188) 27(186) 28(198) 29(178) 30(217) 31(185) 32(172) 33(223) 34(147) 35(203) 36(167) 37(188) 38(152) 39(165) 40(187) 41(160) 42(199) 43(140) 44(202) 45(186) 46(182) 47(175) 48(161) 49(179) 50(175) 51(201) 52(195) 53(205) 54(183) 55(155) 56(178)
```
part 3
` let q=Seq.item 749 (randLS 42)for n in [0..41] do (for g in [0..41] do printf "%3d" q.[n,g]); printfn "" `
Output:
``` 16  7 41 15 17 40 12  9 10  5 19 29 21 18  8 22  3 36 23 31 11 38 13 30  2 33  6 42 39 14 32 20 28 35 26  1 34 37 27 24  4 25
38 25 36 32 40 29 35 27  8 26 31 15  9  7 16 11  4  3 12 20 23 33  5 24 41 14 30 34 42 17 39 18 37 22 21 13  1 10  6 19  2 28
8 34 27 25 21 31  1 23 37 36 26 13 22 24 35 17 10 40 41 30 42  7 15  2 18  3 29 11 32  4 38 39  9  5 16 14 28 12 20 33 19  6
33 35 13 34 15 24  4 29 41 27  3 17 10 26 39 23 30 32  1 38 16 25 37 14  6 28 19  9 40  5 18  7 42 11 31 20 12 22  2 21  8 36
2 42 20  1  7 26 11 10 39 41 34 22 40 23 24 29 14 17  5 33 38 30  6 13  3 16 18 19 31 15 28 21 36 37 32 27  8  4 25  9 35 12
25 33 14 40 28 30 31 24 29  4  8 20 26 38 12 35  2 39 16  6 13 21 18 17  5 41 23  3 36  7 34 22 27  1 10 42 11 19 15 32 37  9
17 22 35 28 30 18 21  2 15 39  5 40 27 13  1 34 38 37 26 23 41 36  4  3 11  6 20  8  9 10 12 24 31 25  7 29 16 32 42 14 33 19
14  9 19  7 26 15 10  4 36 25 22 23 39 16  2 40 18  1 38 13 21 37 34 31 35 24 12 27 11  3  5  6 17 20 41 33 32 29  8 30 28 42
5 27 24 13  2 36 25 30 23  9  6 14 35 15 42 39 16 26 21 34 33 31  3  1 29 12 38 17 37 19 40  4  7  8 22 41 20 28 32 10 18 11
19 41 28 26  8 10 30 35 18 33 15 27 25 21 29 42 23 12 17  2  5  1 38  6 20  7 34  4 13 36 24 31 14  3 11 32 39 40  9 22 16 37
41 10  3 19 22  9 27 40  1 29 16 42 33 39 34  7 37 20 11 12  4 18 35  8 28 26 36  5 17 30 25 32  6 15 24 21 13 23 14  2 38 31
42  3 16 36 33 21 20 14 31 22  9 38 29 19 37 13 28 10 35 18 39 26 25 27  4 30 15 23 41 24 11  1 40  7  5 17  6  2 12  8 34 32
23 31 34 41 38 33  3 28  4  1 30 25  6  2 20 14 13 24  8 42  7 12 39 32 22 29  5 37 15  9 27 10 35 36 19 40 17 18 16 11 26 21
37 16 30 11  4 32 42 33 13  6 14  2 15 27 18 31 20 41 39 40  9 24 36  5 10  8  1 26  3 34 22 28 38 19 29 23 21 25 35 12 17  7
1 19 26 22 16 25 36 39  3 23 41 37 34  6 17 32 40 21 10 27 12  9 31  7 13  4 24 29  8 11  2  5 15 18 35 28 30 20 33 38 42 14
11 13 23 30 25 41  6 31 14 32 27 36 19 17 10 33 21 15  7  5  8 28 16 35 34 42 40  2 38 39  9 26 20 24 37  4 18  3 22  1 12 29
24 17 29 38 23 39 32  5 11 15 35 12  8 10 40  1 22 25  2 36 28  4 42 21  9 20  3 31 16 41 13 30 19 34 33 18 27  6  7 37 14 26
36  4  6 24 12 20  2 34 40 11 32  9 28  8 38 21  5 31 42 17 14 29 19 22 25 15  7 18 30 26  1 13 16 41 23 39 37 33  3 35 10 27
20 39  2 12 32  7 22  3 17 10 37  6 18 40 27  5 42 35 28  4 24 14 33 29 30 31 26 13 19 23 36 41  1 21  9 11 15  8 34 16 25 38
35 18 37  6  5 13 29  8 24 19 38 34 12 31 21 10 33  7  3 41 15 42 20 11 27 40 16 14 23  1  4  2 22 32 28  9 25 30 26 39 36 17
10 32  9 33 39 19 41 38 35 18 28 26 14 30  7  4  1 22 37 21 31 40 27 15 42 34  2 25  5 12 23 36  8  6 17  3 29 24 11 13 20 16
13 28 39  2 31  8  9 37 21 16 40 19 42 36 41  3 12 14 20 10 17 34  1 33 32 35 25 30 18 38 15 11 24 23  6 26  4  5 29  7 27 22
7 40 12 39 18  3 16 21 42 17  1 32  5 33 13  6 41  8 29 14 34 35 24 36 38 25 31 28 26 27 20 37 23  2 30 10 22  9 19  4 11 15
4 21  7 17 35 34 19 25 12 42 11  1 30 28 36 26 32 23 14 29  2 20  8 41 24 27 22 15 10 18 37  9 39 38 13  6  3 16 31 40  5 33
34 23 42 14 41 27 37  6  9 31  4  5  7  1 25 16 35 30 33 11 19  3 26 12 17 38  8 20 24 13 29 15 32 28 40 22  2 39 18 36 21 10
30  6 21  9 20 17  5 32 38 13 12 28 16 35 22 36 34 29 40 39 25 15 14 37 33 11  4 41  1  2 19  3 26 27 42  8 10  7 23 31 24 18
6 38  8 10 42 35 13  1 16 37 21  3 11 34 32 20 29 18 25 22 36  5 30 26 39 23 28 12  2 31  7 19 33 40 14 24  9 41 17 27 15  4
29 15  1 21 14 11 26 17 30 38 10 33 36 20  4 18 39 16 31  3 35  2 32 28 19 13 42  7 12  8  6 40  5  9 25 37 24 27 41 23 22 34
21 36 32  8  6 23 15 19  2 14 18  4  3 11  5 28 26 13 34 25 30 17  7 42 16 22 39 40 29 37 33 12 41 10 27 31 35 38 24 20  9  1
39 20 31 29 19  4 38 16 27 30 24 11  2  3 33 15  8 28 18 37 10 13  9 23 36  1 17 22 25 32 26 35 12 42 34  7 40 14 21  5  6 41
12 11 17 42  9  2 14  7 22 24 25 31 38 41 15 19 36 33 32 28  1 10 29 40 23 18 37 39  6 21 35 27  3 16  8 30  5 26  4 34 13 20
18 29 33 16 27 42 40 26  7  8 39 24 41  5 30 38  6  9 13  1 32 22  2 34 12 37 11 10 35 20 14 17 21  4 15 19 23 36 28 25 31  3
28  2  4 18 11  5 23 20 25 35 42 30 31 14  3  9 24 27 19  7 22  6 12 10  1 32 41 36 21 33 16 34 29 13 39 15 38 17 37 26 40  8
3 26 11 35 24 37 17 36  6  7 13 41  4 32  9  2 31 34 22 15 29  8 40 18 21  5 27  1 14 16 10 38 25 33 20 12 19 42 39 28 30 23
31  5 22 27 10  6  8 13 34  2 33  7 32 42 26 12 19  4 15  9 40 16 28 38 37 39 35 24 20 29 17 23 11 14  3 25 41 21 36 18  1 30
15 24  5 37  3 28  7 22 19 34 20 18 17 12 23  8 25 11 36 16 27 41 10  4 31  2  9 32 33 42 21 14 13 29 38 35 26  1 30  6 39 40
27 37 25  5 13 16 24 41 28  3  2 10 23  4 14 30 11 38  6 19 26 32 21 20 40  9 33 35 34 22 42  8 18 17 12 36 31 15  1 29  7 39
26 30 10  3 36 22 33 11  5 20 29 21 13 25 31 37 17  2  9 35 18 27 23 39 14 19 32 16 28  6  8 42  4 12  1 38  7 34 40 15 41 24
32  8 18 31  1 14 34 12 33 28 17 39 37  9 19 27  7  5 30 24 20 23 11 25 15 36 21  6 22 40 41 16 10 26  4  2 42 35 38  3 29 13
9 14 40 23 37 38 18 15 20 12 36  8  1 22 28 24 27 42  4 32  6 11 41 19 26 10 13 21  7 25 30 29 34 39  2 16 33 31  5 17  3 35
22 12 15  4 34  1 39 42 32 40  7 35 20 29 11 25  9  6 24 26 37 19 17 16  8 21 14 38 27 28  3 33 30 31 18  5 36 13 10 41 23  2
40  1 38 20 29 12 28 18 26 21 23 16 24 37  6 41 15 19 27  8  3 39 22  9  7 17 10 33  4 35 31 25  2 30 36 34 14 11 13 42 32  5
```
part 4

Generating 1000 Latin Squares of order 256 takes about 1.5secs

` printfn "%d" (Array2D.length1 (Seq.item 999 (randLS 256))) `
Output:
```256
Real: 00:00:01.512, CPU: 00:00:01.970, GC gen0: 10, gen1: 10
```

## Go

The J & M implementation is based on the C code here which has been heavily optimized following advice and clarification by Nigel Galloway (see Talk page) on the requirements of this task.

Part 4 is taking about 6.5 seconds on my Celeron @1.6 GHz but will be much faster on a more modern machine. Being able to compute random, uniformly distributed, Latin squares of order 256 reasonably quickly is interesting from a secure communications or cryptographic standpoint as the symbols of such a square can represent the 256 characters of the various extended ASCII encodings.

`package main import (    "fmt"    "math/rand"    "time") type (    vector []int    matrix []vector    cube   []matrix) func toReduced(m matrix) matrix {    n := len(m)    r := make(matrix, n)    for i := 0; i < n; i++ {        r[i] = make(vector, n)        copy(r[i], m[i])    }    for j := 0; j < n-1; j++ {        if r[0][j] != j {            for k := j + 1; k < n; k++ {                if r[0][k] == j {                    for i := 0; i < n; i++ {                        r[i][j], r[i][k] = r[i][k], r[i][j]                    }                    break                }            }        }    }    for i := 1; i < n-1; i++ {        if r[i][0] != i {            for k := i + 1; k < n; k++ {                if r[k][0] == i {                    for j := 0; j < n; j++ {                        r[i][j], r[k][j] = r[k][j], r[i][j]                    }                    break                }            }        }    }    return r} // 'm' is assumed to be 0 basedfunc printMatrix(m matrix) {    n := len(m)    for i := 0; i < n; i++ {        for j := 0; j < n; j++ {            fmt.Printf("%2d ", m[i][j]+1) // back to 1 based        }        fmt.Println()    }    fmt.Println()} // converts 4 x 4 matrix to 'flat' arrayfunc asArray16(m matrix) [16]int {    var a [16]int    k := 0    for i := 0; i < 4; i++ {        for j := 0; j < 4; j++ {            a[k] = m[i][j]            k++        }    }    return a} // converts 5 x 5 matrix to 'flat' arrayfunc asArray25(m matrix) [25]int {    var a [25]int    k := 0    for i := 0; i < 5; i++ {        for j := 0; j < 5; j++ {            a[k] = m[i][j]            k++        }    }    return a} // 'a' is assumed to be 0 basedfunc printArray16(a [16]int) {    for i := 0; i < 4; i++ {        for j := 0; j < 4; j++ {            k := i*4 + j            fmt.Printf("%2d ", a[k]+1) // back to 1 based        }        fmt.Println()    }    fmt.Println()} func shuffleCube(c cube) {    n := len(c[0])    proper := true    var rx, ry, rz int    for {        rx = rand.Intn(n)        ry = rand.Intn(n)        rz = rand.Intn(n)        if c[rx][ry][rz] == 0 {            break        }    }    for {        var ox, oy, oz int        for ; ox < n; ox++ {            if c[ox][ry][rz] == 1 {                break            }        }        if !proper && rand.Intn(2) == 0 {            for ox++; ox < n; ox++ {                if c[ox][ry][rz] == 1 {                    break                }            }        }         for ; oy < n; oy++ {            if c[rx][oy][rz] == 1 {                break            }        }        if !proper && rand.Intn(2) == 0 {            for oy++; oy < n; oy++ {                if c[rx][oy][rz] == 1 {                    break                }            }        }         for ; oz < n; oz++ {            if c[rx][ry][oz] == 1 {                break            }        }        if !proper && rand.Intn(2) == 0 {            for oz++; oz < n; oz++ {                if c[rx][ry][oz] == 1 {                    break                }            }        }         c[rx][ry][rz]++        c[rx][oy][oz]++        c[ox][ry][oz]++        c[ox][oy][rz]++         c[rx][ry][oz]--        c[rx][oy][rz]--        c[ox][ry][rz]--        c[ox][oy][oz]--         if c[ox][oy][oz] < 0 {            rx, ry, rz = ox, oy, oz            proper = false        } else {            proper = true            break        }    }} func toMatrix(c cube) matrix {    n := len(c[0])    m := make(matrix, n)    for i := 0; i < n; i++ {        m[i] = make(vector, n)    }    for i := 0; i < n; i++ {        for j := 0; j < n; j++ {            for k := 0; k < n; k++ {                if c[i][j][k] != 0 {                    m[i][j] = k                    break                }            }        }    }    return m} // 'from' matrix is assumed to be 1 basedfunc makeCube(from matrix, n int) cube {    c := make(cube, n)    for i := 0; i < n; i++ {        c[i] = make(matrix, n)        for j := 0; j < n; j++ {            c[i][j] = make(vector, n)            var k int            if from == nil {                k = (i + j) % n            } else {                k = from[i][j] - 1            }            c[i][j][k] = 1        }    }    return c} func main() {    rand.Seed(time.Now().UnixNano())     // part 1    fmt.Println("PART 1: 10,000 latin Squares of order 4 in reduced form:\n")    from := matrix{{1, 2, 3, 4}, {2, 1, 4, 3}, {3, 4, 1, 2}, {4, 3, 2, 1}}    freqs4 := make(map[[16]int]int, 10000)    c := makeCube(from, 4)    for i := 1; i <= 10000; i++ {        shuffleCube(c)        m := toMatrix(c)        rm := toReduced(m)        a16 := asArray16(rm)        freqs4[a16]++    }    for a, freq := range freqs4 {        printArray16(a)        fmt.Printf("Occurs %d times\n\n", freq)    }     // part 2    fmt.Println("\nPART 2: 10,000 latin squares of order 5 in reduced form:")    from = matrix{{1, 2, 3, 4, 5}, {2, 3, 4, 5, 1}, {3, 4, 5, 1, 2},        {4, 5, 1, 2, 3}, {5, 1, 2, 3, 4}}    freqs5 := make(map[[25]int]int, 10000)    c = makeCube(from, 5)    for i := 1; i <= 10000; i++ {        shuffleCube(c)        m := toMatrix(c)        rm := toReduced(m)        a25 := asArray25(rm)        freqs5[a25]++    }    count := 0    for _, freq := range freqs5 {        count++        if count > 1 {            fmt.Print(", ")        }        if (count-1)%8 == 0 {            fmt.Println()        }        fmt.Printf("%2d(%3d)", count, freq)    }    fmt.Println("\n")     // part 3    fmt.Println("\nPART 3: 750 latin squares of order 42, showing the last one:\n")    var m42 matrix    c = makeCube(nil, 42)    for i := 1; i <= 750; i++ {        shuffleCube(c)        if i == 750 {            m42 = toMatrix(c)        }    }    printMatrix(m42)     // part 4    fmt.Println("\nPART 4: 1000 latin squares of order 256:\n")    start := time.Now()    c = makeCube(nil, 256)    for i := 1; i <= 1000; i++ {        shuffleCube(c)    }    elapsed := time.Since(start)    fmt.Printf("Generated in %s\n", elapsed)}`
Output:

Sample run:

```PART 1: 10,000 latin Squares of order 4 in reduced form:

1  2  3  4
2  1  4  3
3  4  2  1
4  3  1  2

Occurs 2550 times

1  2  3  4
2  4  1  3
3  1  4  2
4  3  2  1

Occurs 2430 times

1  2  3  4
2  1  4  3
3  4  1  2
4  3  2  1

Occurs 2494 times

1  2  3  4
2  3  4  1
3  4  1  2
4  1  2  3

Occurs 2526 times

PART 2: 10,000 latin squares of order 5 in reduced form:

1(165),  2(173),  3(167),  4(204),  5(173),  6(165),  7(215),  8(218),
9(168), 10(157), 11(205), 12(152), 13(187), 14(173), 15(215), 16(185),
17(179), 18(176), 19(179), 20(160), 21(150), 22(166), 23(191), 24(181),
25(179), 26(192), 27(187), 28(186), 29(176), 30(196), 31(141), 32(187),
33(165), 34(189), 35(147), 36(175), 37(172), 38(162), 39(180), 40(172),
41(189), 42(159), 43(197), 44(158), 45(178), 46(179), 47(193), 48(175),
49(207), 50(174), 51(181), 52(179), 53(193), 54(171), 55(153), 56(204)

PART 3: 750 latin squares of order 42, showing the last one:

29  2 17 41 34 30  8 33 39  7 20 27 12  6 31 14 40 35 25  9 10 32 19 16 24 42  3 26  5 23  1 28  4 13 38 18 21 37 22 15 36 11
17 15 11 31  9 38 26 10  1 28 37  8 34 41 21 22 12  5 35 36 13 20 29 42 18  3 19 24 39 32 27 23 16 25 33  4 40  6  2 30  7 14
36 42 35 39 15 34 37 18 32 25 22 31  4 17  3 19 13 11  8 23 12 24 28 27 16  1  6  9 29 40  7  5  2 14 30 26 41 10 21 33 38 20
21 13 16 42  3 32  2 26 27 17 15 11 25 37 29  6 19 10 12  7 31 18 36  9 39 41 30 40 35 33 22  1 28 38 24  8 34 23  4 20 14  5
22 39 13  7 38  9 34 41 37 36 35  6 21 26 17 16  4 30 40 20  8 15 25 19 32  2 11 28 23 24 31 10 42  3 27 12 33 14  1 29  5 18
33 36 34  3 13  4  7 14  2 29  6 12 31 23 26 17  8 20 32 21 19 41 37  5 38 30 25 11 24 35 42 27 18 16 39 15 10 22 28  1  9 40
14 31  7 22 39 23 32 34 16 33 24  4 40 42 12 25 35 26 18 28 11  3 15 21 20  9 13 19  1 10  2 41 29  6 17 30  5 38 37  8 27 36
9  3  6 30 19 39 14 16  4 15 29 28 23 24 32 10 18 41 37 38 40 34  8 25  2 22 31  5 17 26 36 33 13 21 12 35  7 20 11 27 42  1
2 18 28  5  6  7 40 35  3 20  8 34 42 39 37 33 26 23 22 13 14  4 12 15 17 25 36 31 16 29 38 19 32 41  1 27 24 11 30  9 10 21
27 34 19 15 33 22  5 36  9 30 14  1 24  8 38 42 41 39  7 40  4 37 11 23 29 26 18 12  3 21 35 16 20 10 31 25 17 28  6 32  2 13
41 16  1 35 22 13 20 29  6 38  5 24 19 10 25 27 17 18 11 32  9  7  2 36  4 34 40 21 33 12  8 30 15 42 37 23 14 26  3 39 31 28
7  1 15 16 27 31 18 24 20  8 36 38 10 34  9  4 42 29  2  3 26 39  5 22 41 21 37 30 14 11 33 35 25 23 40 28 13 19 17  6 32 12
1 10 20 32 23  5 30 12  8  9 21 36 15 14 18 37 33 31 26 39 41 16  6 24 22 35 29 42 27 28  3 38 11  2  7 34  4 40 19 17 13 25
6 32 42 11 20 40 27 25 41 22 17 16 26 29 15  7 23 36 39 34 28 13 18  3 10 37  8 14  2 31  4 24  5 19  9 21 38  1 33 12 30 35
35 40 30 19 21 12 17  4 22 27  3 20 11  9  8 23 24 42 14 10 39 28 26 29 33 13 41 16 34 25 32 37  7 18  5  6 15  2 36 38  1 31
15 26 40  1 28 20  9 21  7  5 13 18 30 22 10  8  3 25  6  2 17 36 38 31 14 19 35 23 12 27 11 39 24  4 41 32 29 34 42 16 37 33
3  6 26 12 32  1 13  8 42 37 25  7  9 16 35  5 29 21 24 27 34 17 14  2 15 11 28 33 20 38 18 22 39 40 23 10 31 30 41 36 19  4
31 38 36 21 16 26 28 30 15  3 32 41 18  1  6 29  9 17  5 35  7 40 27 37 13 20 23 22 11 19 12 42 34  8 10 14 25 39 24  4 33  2
40  4 22 38 35 11 21 17 31  1 28 19 37  2 42 24 14 12 13 30 33 25 34 32 27 36 39  3  9 15 10 18  8  5  6 41 26 16 29  7 20 23
5 17 39  4 26 14 31 37 35 11 38  3  1 30 19 36 20 33 15 16 21 29  9  6 25 27  2 13 41 34 24 12 10 32 22  7 28 18 40 42 23  8
8 29 24 26 31 21 39 23 11 14 19 10 20 15  7 35 32 38  1 12 25 22 16  4  6 40 42 41 18 30 28  2 17 36  3 13 37 33 27  5 34  9
11 25 14 17 18 24 19 32 33 31  7 26  2 21 20 30 15 27 23 41 29 35 39 28 34 12 10  4  8 42  5 13 37  9 16 40  1 36 38  3  6 22
26 21 18 25 29 15  1 13 19  2 34 23 38 27 41  3 10 22 17  4 16 11 42 12  8  6  5 35 30 39 37 14  9 24 36 33 20  7 31 28 40 32
25 27 12 33 17 35 24  9 28 10 42 21  8 13  2 15 34 16  3 18  5 31 41  7 23  4  1  6 22 14 19 36 40 37 26 38 30 32 20 11 39 29
23 19 25  9 30 37 38 40 14 41 31 17  7  4 16 11  1  6 33  5 24  2  3  8 21 29 34 32 28 22 15 20 12 35 18 36 39 27 10 13 26 42
34  9 10 13  2  6 22 31 26 40  1 14 41  3 11 12 37 32 27 29 35 19 30 33 28 38 21 25  7  5 16  8 36 15 20 42 23 17 39 18  4 24
20 11 37 28 41  8 10 15 36 12 26 33 39 32 13  1 25  9 42 19  3  6 24 14  5 23  7 27 38  2 30  4 22 34 35 31 18 29 16 40 21 17
28 30 21 23 24 29  3  1 10  6 33  2 27 40 14 34 31 15 19 37 18  9  4 13 35  8 12 20 36 16 17 32 41  7 25 39 42  5 26 22 11 38
32 12  8 40 11 16 23 28 18 42 41 30  3 38 33  2 22 19  4 25 37  1 31 20 36  5  9  7 13 17 14  6 27 39 34 24 35 21 15 26 29 10
18 37 41 10 36 28 11 42 13 34  2 35  5  7 22 40 39  3 30  1 38 27 20 17 19 33 26 15 25  6 21 29 23 31  4  9 32  8 12 14 24 16
39 24 29 37 25 19 33 27 17 16 10 40 36 12 30 41 11  4 34 15  2  5 32  1 31 14 38 18 42  3  9  7  6 20 21 22  8 13 23 35 28 26
19 14  5  8 40  3 29  6 21 26 23 15 16 33 28 31 38 13  9 17 27 12 10 11  7 24 20  1  4 41 39 25 30 22 32  2 36 42 35 34 18 37
37  7 32 34  8 36 41  2 12 24 16 39 33 31  4 13  6 28 38 22 20 42 40 18  9 10 14 29 26  1 23 15 21 27 19 17 11  3  5 25 35 30
4 41 27  2 42 17 15 38 30 35 12 25 13 28 39 20  5  1 16 33 36 23  7 40 37 32 24 10 31  8  6 21 14 26 29 11  3  9 18 19 22 34
38 35 23 36  4 10 12 11  5 21 27 32 17 25 24 18 28 40 20  6 42 14 22 30 26 39 33  8 37  7 13 34  1 29 15 19  2 41  9 31 16  3
30 33 31 24 12 41 36 19 23 32  4 37 29 11 34 39 16 14 21 42  6 26  1 38  3 17 22  2 40 18 20  9 35 28 13  5 27 15 25 10  8  7
42 28  3 14  1 25 16 22 34 23 39  9 35  5 40 26 36  7 10 31 32 21 13 41 30 18  4 38  6 37 29 17 33 12 11 20 19 24  8  2 15 27
16  5 38  6 10 27  4  3 40 18 11 13 22 35  1 21  2 34 36  8 23 30 17 39 42  7 15 37 32 20 26 31 19 33 28 29  9 25 14 24 12 41
24 23 33 18 14  2 25 39 29 19  9  5 28 20 27 38  7  8 31 11 15 10 35 34 12 16 32 17 21 36 40  3 26 30 42  1 22  4 13 37 41  6
12 20  2 29  5 33 42  7 24  4 18 22 14 19 36  9 27 37 28 26 30 38 23 10 11 31 17 34 15 13 41 40  3  1  8 16  6 35 32 21 25 39
13  8  9 27 37 42  6 20 25 39 40 29 32 18  5 28 30 24 41 14 22 33 21 35  1 15 16 36 10  4 34 26 38 11  2  3 12 31  7 23 17 19
10 22  4 20  7 18 35  5 38 13 30 42  6 36 23 32 21  2 29 24  1  8 33 26 40 28 27 39 19  9 25 11 31 17 14 37 16 12 34 41  3 15

PART 4: 1000 latin squares of order 256:

Generated in 6.581088256s
```

## Phix

Translation of: Go
`function shuffleCube(sequence c)    integer n = length(c), rx, ry, rz    bool proper = true    while true do        rx = rand(n)        ry = rand(n)        rz = rand(n)        if c[rx][ry][rz] == 0 then exit end if    end while    while true do        integer ox, oy, oz        for ox=1 to n do            if c[ox][ry][rz] == 1 then exit end if        end for        if not proper and rand(2)==2 then            for ox=ox+1 to n do                if c[ox][ry][rz] == 1 then exit end if            end for        end if        for oy=1 to n do            if c[rx][oy][rz] == 1 then exit end if        end for        if not proper and rand(2)==2 then            for oy=oy+1 to n do                if c[rx][oy][rz] == 1 then exit end if             end for        end if        for oz=1 to n do            if c[rx][ry][oz] == 1 then exit end if        end for        if not proper and rand(2)==2 then            for oz=oz+1 to n do                if c[rx][ry][oz] == 1 then exit end if            end for        end if         c[rx][ry][rz] += 1        c[rx][oy][oz] += 1        c[ox][ry][oz] += 1        c[ox][oy][rz] += 1         c[rx][ry][oz] -= 1        c[rx][oy][rz] -= 1        c[ox][ry][rz] -= 1        c[ox][oy][oz] -= 1         if c[ox][oy][oz] < 0 then            {rx, ry, rz} = {ox, oy, oz}            proper = false        else            proper = true            exit        end if    end while    return cend function function toMatrix(sequence c)    integer n = length(c)    sequence m = repeat(repeat(0,n),n)    for i=1 to n do        for j=1 to n do            for k=1 to n do                if c[i][j][k] != 0 then                    m[i][j] = k                    exit                end if            end for        end for    end for    return mend function function toReduced(sequence m)    integer n := length(m)    for j=1 to n-1 do        if m[1][j]!=j then            for k=j+1 to n do                if m[1][k]==j then                    for i=1 to n do                        {m[i][j], m[i][k]} = {m[i][k], m[i][j]}                    end for                    exit                end if            end for        end if    end for    for i=2 to n-1 do        if m[i][1]!=i then            for k=i+1 to n do                if m[k][1]==i then                    for j=1 to n do                        {m[i][j], m[k][j]} = {m[k][j], m[i][j]}                    end for                    exit                end if            end for        end if    end for    return mend function function makeCube(object from, integer n)    sequence c = repeat(repeat(repeat(0,n),n),n)    for i=1 to n do        for j=1 to n do            integer k = iff(from==NULL?mod(i+j,n)+1:from[i][j])            c[i][j][k] = 1        end for    end for    return cend function procedure main()     printf(1,"Part 1: 10,000 latin Squares of order 4 in reduced form:\n\n")    sequence from = {{1, 2, 3, 4}, {2, 1, 4, 3}, {3, 4, 1, 2}, {4, 3, 2, 1}},             c := makeCube(from, 4), m, rm, fk    integer freq = new_dict()    for i=1 to 10000 do        c = shuffleCube(c)        m = toMatrix(c)        rm = toReduced(m)        setd(rm,getd(rm,freq)+1,freq)    end for    fk = getd_all_keys(freq)    for i=1 to length(fk) do        printf(1,"%v occurs %d times\n", {fk[i],getd(fk[i],freq)})    end for     printf(1,"\nPart 2: 10,000 latin squares of order 5 in reduced form:\n\n")    from = {{1, 2, 3, 4, 5}, {2, 3, 4, 5, 1}, {3, 4, 5, 1, 2},            {4, 5, 1, 2, 3}, {5, 1, 2, 3, 4}}    c = makeCube(from, 5)    destroy_dict(freq, justclear:=true)    for i=1 to 10000 do        c = shuffleCube(c)        m = toMatrix(c)        rm = toReduced(m)        setd(rm,getd(rm,freq)+1,freq)    end for    fk = getd_all_keys(freq)    for i=1 to length(fk) do        fk[i] = sprintf("%2d(%3d)", {i,getd(fk[i],freq)})    end for    puts(1,join_by(fk,8,7," ","\n"))    destroy_dict(freq)     -- part 3    printf(1,"\nPart 3: 750 latin squares of order 42, showing the last one:\n\n")    c = makeCube(NULL, 42)    for i=1 to 750 do        c = shuffleCube(c)    end for    m = toMatrix(c)    integer n := length(m)    for i=1 to n do        for j=1 to n do            m[i,j] = sprintf("%2d",m[i,j])        end for        m[i] = join(m[i]," ")    end for    printf(1,"%s\n",join(m,"\n"))     -- part 4    printf(1,"\nPART 4: 1000 latin squares of order 256:\n\n")    atom t0 = time()    c = makeCube(NULL, 256)    for i=1 to 1000 do        c = shuffleCube(c)    end for    printf(1,"Generated in %s\n", elapsed(time()-t0))end proceduremain()`
Output:
```Part 1: 10,000 latin Squares of order 4 in reduced form:

{{1,2,3,4},{2,1,4,3},{3,4,1,2},{4,3,2,1}} occurs 2503 times
{{1,2,3,4},{2,1,4,3},{3,4,2,1},{4,3,1,2}} occurs 2560 times
{{1,2,3,4},{2,3,4,1},{3,4,1,2},{4,1,2,3}} occurs 2510 times
{{1,2,3,4},{2,4,1,3},{3,1,4,2},{4,3,2,1}} occurs 2427 times

Part 2: 10,000 latin squares of order 5 in reduced form:

1(172)  9(197) 17(228) 25(166) 33(171) 41(224) 49(171)
2(168) 10(162) 18(216) 26(227) 34(172) 42(155) 50(226)
3(159) 11(198) 19(206) 27(165) 35(189) 43(190) 51(174)
4(170) 12(207) 20(159) 28(166) 36(177) 44(171) 52(196)
5(211) 13(148) 21(172) 29(173) 37(183) 45(189) 53(197)
6(169) 14(163) 22(128) 30(179) 38(184) 46(138) 54(173)
7(168) 15(155) 23(146) 31(170) 39(187) 47(170) 55(206)
8(193) 16(177) 24(146) 32(176) 40(157) 48(183) 56(177)

Part 3: 750 latin squares of order 42, showing the last one:

5 29 15  7 25 26  2 35 21 39  8 12 17 31  3 20 23 22 40 34 13 32 27 38  9  6 36 41 11 19  4 42 10 28 33 18 30 16  1 14 37 24
34 17 22 12 38 28 20 42 15 10  4  3 30 16 35 23 11 19 31  8 32  1 33 36 24  2 18 39  9 41 40 26 25 27 29  5  7 37 21 13  6 14
23 14 41 38  2 36  4 34 29 16 11 10 24 13 26 31 30 12 28 18  7 21 40 42 27  9 37 35  1  3 17 22 20  5  6 33 32 39 25 19 15  8
29 21 27 41  3 10 12 23  4 18 39  1 11  6 20 34  2 35 36 37 40  5 14 26 17 42 24 33 32 16 28  8 13 30 15  9 25 19 38  7 31 22
8 32 10 17 30 15 18 13 19  6 26 29 34 42 28 40 24 23 33  7  3  4 12 37 38 36  1 21 41 20 16 25  5 11  2 39 14 22 31 35  9 27
27 40 39 16 11 23 14 20  6  4 19 28 36 12 31 24 42 10 35 33 17 18 30  3 21  5 38 15  7  1  9 34  8 32 37 13  2 26 29 22 25 41
31 39 29 22 20  6 11 17 16 19 41 36 35 33 30 14  4  2 15 24 21 10 25  1 18 12 40 28  5 37 32 27  3 13 42 38  9 34 26  8  7 23
11 33 42 28 14  7  6 24 37 26 13 35  9  5 19 18 15 20 25 41 30 17  3 12 22  8 21 27 39 10 34 40 32 36  4 31 23 29  2 38 16  1
20 11  7  8 32 31 40 37 42 13 21 22 26  2 12 29  1 27  6 14 19 41 38 17 36 25  4  5 30 15 24 35 16 34 39  3 28 23  9 18 33 10
24  9 28 40 33 29  3  7 34 11 16 27  2 30 42 25 21 13 41 10 38  8 39 35 12 26 19 20 23 31  5 32  1 22 14  6  4 15 37 36 17 18
2  8 23 37 27  9 38 36 13 24 31 14 29  7  6 42  3 34 18 32  1 20 22 41 25 30 33 16 15  4 11 10 26 39 21 28 17 40 19  5 12 35
13  2 26 15 10 40 39  6 33 29 42 34 12 17 11 28 22 32 14 25 24 37 21  5  8 23 30  9 18  7 41 31  4  3 27 19 16 35 20  1 38 36
22 23 34 31 28 25 36 38  9 32 30  8  3 11 17 41 26 39 24  6  2 35 13  4  7 21 29 18 14 27 19 37 15 20 16 12 10 33 40 42  1  5
36 28 20 11 29 39 22 41 35  7  5 15 31 24  8 19 27 37  1 38 16 13  6  2 32 40 14 25 33 17 21  4 34 23 30 10 18 42 12  9 26  3
6 25  8  2 17 33 19 12  1 38 40 39  5 32 18  7 34 30  9 11 15  3 31 23 37 24 27 14 20 28 36 16 21 42 13 29 41  4 35 10 22 26
14 24 38 32 12  3 15  2 17 28 36 40 19 26  1 27 29 41  8  5 23 42 20 13 10 34  6 31 16 35 30  7 11 18 22 21 33 25  4 37 39  9
39 30  5 20  1 22  9 40 36 27  7 33 37 18 29 38 25 42  4 21 14 31 10 28 26 15 16  8  3 13 35 19 41  2 32 24 12 11 17 23 34  6
35 18 17 14 13 41 25 31  2  3 32 24 10 19 22 33  6  1 16 23  9 15  8 39  5  7 11 12 42 34 37 28 38  4 26 20 40 36 27 21 30 29
9 19 24 26 42 16  7 30 10 40 29  4 33  8 38 22 14 25 37 28  5 27 41 32  1 13 17 36 34 39 23 11 31  6 35  2 20 21 18 15  3 12
12 22 37  1  4 20 32  3 30 25 28 26  6 14 36 11 39 21 38 29 27 24  7 16 15 31  9 34 10 33 13 18 40 35  5 17 19  8 42 41 23  2
3 16 31 42  7 17 37 25 23 36 15 18 27 22  5 21 40  9 10 39  4 26 29  6  2 33 41 19 35  8 12 20 28 38 24 32 11  1 34 30 14 13
19 41 36 34 21 18 26 29 27 20 14 16 38 40  7 15 32  3 17  4 10 28 35 33 13 22  8  6 25 42 31 23  2 37  9 30  1 12  5 24 11 39
25  4 12 29 26 37 16  9 22 30  6 23 40 21 15 35 20 38 19 42 11  2  1 18  3 41  5 10 28 36 33 39 27 24 34  8 31 32 14 17 13  7
41 12 14 33 40 35 28 15  7  9  1  5 13 23 27 32  8 17 26 31 42 34 37 19 30 38 20 22  2  6 39 21 36 29 18 16  3 24 11  4 10 25
26 20  3 19 16 30  5 14  8 41 10  7 25 15 21 13 38 36 39 22 28 23 17 27 33 37 34 32  4  2 29 12  9 31  1 42 24 18  6 40 35 11
10  1 25 36 37 24  8 26  3 12 34 42 18 38 41 16  9 14 32 35 31 30  5 22 39 27  7  4 13 29  6 15 23 19 28 11 21  2 33 20 40 17
37 35 40 13 39  8 31 33 38 15 12 32 16 41 34  6  5 11 30 27 20 22 26 14 29 18 28 23 36 21 25  2  7  1 17  4 42  9 10  3 24 19
30 34  2 24 35  1 23 10 20 42 22 37 15 39  9 17 12  4  5 26 18 38 16 29 31  3 25 11 21 14  8 41  6 40 19  7 13 27 28 32 36 33
16  7 19 21 18 27 29 22 39 35  2 38 28 20 40  9 36  8 12  1 41 33 15 31 11 10 42 24  6 32 26 17 37 14 25 23  5 13  3 34  4 30
32  3 11 25  5 12  1  4 18 31 33 19 41  9 37 10  7 24 13 40  6 16 42 21 34 20 26  2 38 22 15 14 35 17 23 36  8 30 39 27 29 28
1 13 30 39 36  4 34 32 12 14 17  6 23 27 24  3 41 40 11 20 22  9 28 15 42 16  2 29 31  5  7 33 19 21 10 35 26 38  8 25 18 37
18 38  4 23 41 19 35 21 26 33 37 20 42 28 13  5 10  7  3 15 25 39 32  9 14 17 31 40 29 24  1 36 30  8 12 34 27  6 22 11  2 16
4 27 21  3  8 42 41 16 40 37 18  2 22 25 32 36 17  5 23 30 29  6  9 34 19 35 15 13 24 11 14  1 12 10 38 26 39 20  7 33 28 31
40 26  9 30  6 21 42 19  5  2  3 31  4 35 23 37 28 15 20 13 34 12 11  8 16 14 39 17 22 25 27 38 18 33  7  1 36 10 24 29 41 32
28 15  1  4 19 11 24  5 31  8 23 17 21 34 14 26 37 18  7  2 35 29 36 10  6 39 32 30 27 38  3  9 33 16 20 25 22 41 13 12 42 40
21 10 35 27 31  2 13 39 28  5  9 41  1 36  4  8 19 29 34 16 33 40 24 25 20 11 22  7 12 18 42 30 14 26  3 37 15 17 23  6 32 38
17 42 18  6 23  5 33  1 24 34 35 30  7 37 16 12 31 26 21 19 39 14  4 11 41 32 10  3 40  9 38 13 22 25 36 27 29 28 15  2  8 20
42  6 13 35 22 32 10  8 14 21 24 11 39  1  2  4 18 33 27  9 12 25 23 40 28 29  3 26 37 30 20  5 17 41 31 15 38  7 36 16 19 34
7 36 16  5  9 34 21 11 32 22 20 25  8 10 33 30 35 31 29 12 26 19  2 24  4  1 13 38 17 23 18  6 39 15 40 14 37  3 41 28 27 42
15 37 32  9 24 38 27 28 41 17 25 13 20 29 10 39 33  6  2 36  8  7 18 30 35  4 23  1 19 26 22  3 42 12 11 40 34 14 16 31  5 21
33 31  6 18 34 14 17 27 25  1 38 21 32  4 39  2 13 16 42  3 36 11 19  7 23 28 12 37  8 40 10 29 24  9 41 22 35  5 30 26 20 15
38  5 33 10 15 13 30 18 11 23 27  9 14  3 25  1 16 28 22 17 37 36 34 20 40 19 35 42 26 12  2 24 29  7  8 41  6 31 32 39 21  4

PART 4: 1000 latin squares of order 256:

Generated in 19.5s
```

Unfortunately the last part of this task exposes the relatively poor performance of subscripting in phix.