langs a-z

Task/Look-and-say-sequence/Pascal/look-and-say-sequence.pascal

@@ -0,0 +1,39 @@
+program LookAndSayDemo(input, output);
+
+uses
+  SysUtils;
+
+function LookAndSay (s: string): string;
+  var
+    item: char;
+    index: integer;
+    count: integer;
+  begin
+    LookAndSay := '';
+    item := s[1];
+    count := 1;
+    for index:= 2 to length(s) do
+      if item = s[index] then
+        inc(count)
+      else
+      begin
+	LookAndSay := LookAndSay + intTostr(count) + item;
+        item := s[index];
+	count := 1;
+      end;
+      LookAndSay := LookAndSay + intTostr(count) + item;
+  end;
+
+var
+  number: string;
+
+begin
+  writeln('Press RETURN to continue and ^C to stop.');
+  number := '1';
+  while not eof(input) do
+  begin
+   write(number);
+   readln;
+   number := LookAndSay(number);
+  end;
+end.