<?pas
// Fibonacci Sequence: Generating numbers using recursion and memoization.

var memo: array[Integer] of Integer;

// Calculates the Nth Fibonacci number recursively with memoization
function FibonacciRecursive(n: Integer): Integer;
begin
  if n <= 1 then
    Exit(n);
    
  if n in memo then
    Exit(memo[n]);
    
  memo[n] := FibonacciRecursive(n - 1) + FibonacciRecursive(n - 2);
  Result := memo[n];
end;

// Calculates the Nth Fibonacci number iteratively (more efficient)
function FibonacciIterative(n: Integer): Integer;
var
  i: Integer;
  a, b, temp: Integer;
begin
  if n <= 1 then
    Exit(n);
    
  a := 0;
  b := 1;
  
  for i := 2 to n do begin
    temp := a + b;
    a := b;
    b := temp;
  end;
  
  Result := b;
end;

// Main Execution
var n := 10;

PrintLn('<h3>Recursive Approach (with Memoization)</h3>');
PrintLn('Fibonacci(' + IntToStr(n) + ') = ' + IntToStr(FibonacciRecursive(n)));

PrintLn('<hr>');

PrintLn('<h3>Iterative Approach</h3>');
PrintLn('Fibonacci(' + IntToStr(n) + ') = ' + IntToStr(FibonacciIterative(n)));

PrintLn('<hr>');

PrintLn('<h3>Sequence Output (Iterative)</h3>');
var seq := '';
for var i := 0 to n do begin
  if i > 0 then seq := seq + ', ';
  seq := seq + IntToStr(FibonacciIterative(i));
end;
PrintLn(seq);
?>