September Morn Update

2019-09-12 10:33:56 -07:00 · 2019-09-12 10:33:56 -07:00 · aac6731f2c
commit aac6731f2c
parent 4e2d22a71d
6856 changed files with 141342 additions and 21127 deletions
--- a/Task/Permutations/Mathematica/permutations-1.math
+++ b/Task/Permutations/Mathematica/permutations-1.math
@ -0,0 +1,11 @@
+(***Standard list functions:*)
+fold[f_, x_, {}] := x
+fold[f_, x_, {h_, t___}] := fold[f, f[x, h], {t}]
+insert[L_, x_, n_] := Join[L[[;; n - 1]], {x}, L[[n ;;]]]
+
+(***Generate all permutations of a list S:*)
+
+permutations[S_] :=
+ fold[Join @@ (Function[{L},
+       Table[insert[L, #2, k + 1], {k, 0, Length[L]}]] /@ #1) &, {{}},
+   S]
--- a/Task/Permutations/Mathematica/permutations-2.math
+++ b/Task/Permutations/Mathematica/permutations-2.math