all tasks

Task/Sorting-algorithms-Heapsort/J/sorting-algorithms-heapsort-1.j

@@ -0,0 +1,17 @@
+swap=: C.~ <
+
+siftDown=: 4 : 0
+  'c e'=. x
+  while. e > c=.1+2*s=.c do.
+    before=. <&({&y)
+    if. e > 1+c do. c=.c+ c before c+1 end.
+    if. s before c do. y=. y swap c,s else. break. end.
+  end.
+  y
+)
+
+heapSort=: 3 : 0
+  if. 1>: c=. # y do. y return. end.
+  z=. siftDown&.>/ (c,~each i.<.c%2),<y        NB. heapify
+  > ([ siftDown swap~)&.>/ (0,each}.i.c),z
+)

Task/Sorting-algorithms-Heapsort/J/sorting-algorithms-heapsort-2.j

@@ -0,0 +1,5 @@
+   heapSort 1 5 2 7 3 9 4 6 8 1
+1 1 2 3 4 5 6 7 8 9
+
+   heapSort &. (a.&i.) 'aqwcdhkij'
+acdhijkqw