A-M baby

Task/Huffman-coding/J/huffman-coding-1.j

@@ -0,0 +1,14 @@
+hc=: 4 : 0
+ if. 1=#x do. y
+ else. ((i{x),+/j{x) hc (i{y),<j{y [ i=. (i.#x) -. j=. 2{./:x end.
+)
+
+hcodes=: 4 : 0
+ assert. x -:&$ y           NB. weights and words have same shape
+ assert. (0<:x) *. 1=#$x    NB. weights are non-negative
+ assert. 1 >: L.y           NB. words are boxed not more than once
+ w=. ,&.> y                 NB. standardized words
+ assert. w -: ~.w           NB. words are unique
+ t=. 0 {:: x hc w           NB. minimal weight binary tree
+ ((< S: 0 t) i. w) { <@(1&=)@; S: 1 {:: t
+)

Task/Huffman-coding/J/huffman-coding-2.j

@@ -0,0 +1,20 @@
+   ;"1":L:0(#/.~ (],.(<'    '),.hcodes) ,&.>@~.)'this is an example for huffman encoding'
+ t    0 1 0 1 0
+ h    1 1 1 1 1
+ i    1 0 0 1
+ s    0 0 1 0
+      1 0 1
+ a    1 1 0 0
+ n    0 0 0
+ e    1 1 0 1
+ x    0 1 0 1 1
+ m    0 0 1 1
+ p    0 1 1 0 0
+ l    0 1 1 0 1
+ f    1 1 1 0
+ o    0 1 0 0
+ r    0 1 1 1 0
+ u    0 1 1 1 1
+ c    1 0 0 0 0
+ d    1 0 0 0 1
+ g    1 1 1 1 0