Initial data commit

Task/Move-to-front-algorithm/Icon/move-to-front-algorithm.icon

@@ -0,0 +1,29 @@
+procedure main(A)
+    every writes(s := !A, " -> [") do {
+        every writes(!(enc := encode(&lcase,s))," ")
+        writes("] -> ",s2 := decode(&lcase,enc))
+        write((s == s2, " (Correct)") | " (Incorrect)")
+        }
+end
+
+procedure encode(m,s)
+    enc := []
+    every c := !s do {
+        m ?:= reorder(tab(i := upto(c)),move(1),tab(0))
+        put(enc,i-1)   # Strings are 1-based
+        }
+    return enc
+end
+
+procedure decode(m,enc)
+    dec := ""
+    every i := 1 + !enc do {	# Lists are 1-based
+        dec ||:= m[i]
+        m ?:= reorder(tab(i),move(1),tab(0))
+        }
+    return dec
+end
+
+procedure reorder(s1,s2,s3)
+    return s2||s1||s3
+end