Initial data commit

Task/Josephus-problem/J/josephus-problem-1.j

@@ -0,0 +1,2 @@
+   3 ([ (1 }. <:@[ |. ])^:(1 < #@])^:_ i.@]) 41
+30

Task/Josephus-problem/J/josephus-problem-2.j

@@ -0,0 +1,7 @@
+   DropNext=. 1 }. <:@[ |. ]
+   MoreThanOne=. 1 < #@]
+   WhileMoreThanOne=. (^:MoreThanOne f.) (^:_)
+   prisoners=. i.@]
+
+   [ DropNext WhileMoreThanOne prisoners f.
+[ (1 }. <:@[ |. ])^:(1 < #@])^:_ i.@]

Task/Josephus-problem/J/josephus-problem-3.j

@@ -0,0 +1,15 @@
+Josephus =: dyad define NB. explicit form, assume executioner starts at position 0
+ NB. use:  SKIP josephus NUMBER_OF_PRISONERS
+ N =: y
+ K =: N | x
+ EXECUTIONER =: 0
+ PRISONERS =: i. N
+ kill =: ] #~ (~: ([: i. #))
+ while. 1 (< #) PRISONERS do.
+  EXECUTIONER =: (# PRISONERS) | <: K + EXECUTIONER
+  PRISONERS =: EXECUTIONER kill PRISONERS
+ end.
+)
+
+   3 Josephus 41
+30

Task/Josephus-problem/J/josephus-problem-4.j

@@ -0,0 +1,5 @@
+   NB. this is a direct translation of the algo from C code above.
+   Josephus2 =: 4 : '(| x&+)/i. - 1+y'
+
+   3 Josephus2 41
+30