Data commit

Task/Run-length-encoding/Pascal/run-length-encoding.pas

@@ -0,0 +1,51 @@
+Program RunLengthEncoding(output);
+
+procedure encode(s: string; var counts: array of integer; var letters: string);
+  var
+    i, j: integer;
+  begin
+    j := 0;
+    letters := '';
+    if length(s) > 0 then
+    begin
+      j := 1;
+      letters := letters + s[1];
+      counts[1] := 1;
+      for i := 2 to length(s) do
+        if s[i] = letters[j] then
+          inc(counts[j])
+        else
+        begin
+          inc(j);
+          letters := letters + s[i];
+          counts[j] := 1;
+        end;
+    end;
+  end;
+
+procedure decode(var s: string; counts: array of integer; letters: string);
+  var
+    i, j: integer;
+  begin
+    s := '';
+    for i := 1 to length(letters) do
+      for j := 1 to counts[i] do
+        s := s + letters[i];
+  end;
+
+var
+  s: string;
+  counts: array of integer;
+  letters: string;
+  i: integer;
+begin
+  s := 'WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWW';
+  writeln(s);
+  setlength(counts, length(s));
+  encode(s, counts, letters);
+  for i := 1 to length(letters) - 1 do
+    write(counts[i], ' * ', letters[i], ', ');
+  writeln(counts[length(letters)], ' * ', letters[length(letters)]);
+  decode(s, counts, letters);
+  writeln(s);
+end.