Data update

Task/Sorting-algorithms-Strand-sort/M2000-Interpreter/sorting-algorithms-strand-sort.m2000

@@ -0,0 +1,68 @@
+module Strand_sort{
+	function strand_sort(aa as array) {
+		function mergelist(sa, sb) {
+			flush ' empty current stack
+			variant v, g
+			integer L=3
+			while len(sa) and len(sb)
+				if L=1 else stack sa {read v}
+				if L=2 else stack sb {read g}		 		
+				if v<g then
+					data v: L=2
+				else
+					data g:L=1
+				end if
+			end while
+			' dump stacks to current stack
+			If L=1 then data v
+			if L=2 then data g				
+			data !sa, !sb
+			' return the current stack as-is
+			=[]
+		}
+		function strand(&a) {
+			flush
+			variant v, g
+			if len(a)<1 then =a:exit
+			stack a {read v }: data v
+			i=1
+			L=0
+			while i <= len(a)
+				if i<>L then
+					stack a {
+						shift i  ' get i_th item as top
+						over  ' copy one
+						read g ' read in a variant
+						shiftback i ' send back to i
+					}
+					L=i
+				end if
+				if g > v then
+					stack a {
+						shift i
+						drop
+					}
+					data g
+					v = g
+				else
+					i++
+				end if
+			end while
+			=[]
+		}
+			
+		a=stack(aa)
+		out = strand(&a)
+		while len(a)
+			out = mergelist(out, strand(&a))
+		end while
+		=array(out)
+	}
+	m = (1, 6, 3, 2, 1, 7, 5, 3)
+	Print m
+	Print strand_sort(m)
+	m = ("aa", "cc", "bb", "a1")
+	Print m
+	Print strand_sort(m)
+}
+Strand_sort