Pascal's Triangle in Pascal

.pas

program PascalsTriangle;

uses crt;

var
  triangle: array[1..20, 1..20] of integer;
  i, j, n: integer;

begin
  clrscr;
  write('Enter number of rows (max 20): ');
  readln(n);

  { Generate Pascal's Triangle }
  for i := 1 to n do
  begin
    triangle[i, 1] := 1;
    triangle[i, i] := 1;
    for j := 2 to i - 1 do
      triangle[i, j] := triangle[i - 1, j - 1] + triangle[i - 1, j];
  end;

  { Display Pascal's Triangle }
  writeln;
  for i := 1 to n do
  begin
    for j := 1 to n - i do
      write('  ');  { Print leading spaces for alignment }

    for j := 1 to i do
      write(triangle[i, j]:4);  { Print values with spacing }

    writeln;
  end;

  readln;
end.