Data update

Task/Move-to-front-algorithm/PascalABC.NET/move-to-front-algorithm.pas

@@ -0,0 +1,37 @@
+const
+  SymbolTable = Lst('a'..'z');
+
+function encode(s: string): list<integer>;
+begin
+  result := new List<integer>;
+  var symtable := SymbolTable;
+  foreach var c in s do
+  begin
+    var idx := symtable.IndexOf(c);
+    result.add(idx);
+    symtable.RemoveAt(idx);
+    symtable.Insert(0, c);
+  end;
+end;
+
+function decode(s: list<integer>): string;
+begin
+  var symtable := SymbolTable;
+  foreach var idx in s do
+  begin
+    var c := symtable[idx];
+    result += c;
+    symtable.RemoveAt(idx);
+    symtable.Insert(0, c);
+  end;
+end;
+
+begin
+  foreach var word in ['broood', 'babanaaa', 'hiphophiphop'] do
+  begin
+    var encoded := encode(word);
+    var decoded := decode(encoded);
+    var status := if decoded = word then 'correctly' else 'incorrectly';
+    println(word, 'encodes to', encoded, 'which', status, 'decodes to', decoded);
+  end;
+end.