Invert the array without using additional arrays.

program mirror;
const n = 20; // sets the number of array elements
var a: array [1..n] of integer;
temp: integer;
begin
randomize;
// Form the array
for i: integer: = 1 to n do
begin
a [i]: = random (n);
write (a [i]: 3);
end;
writeln ();
// Reverse the array
for i: integer: = 1 to trunc (n / 2) do
begin
temp: = a [i];
a [i]: = a [n + 1 – i];
a [n + 1 – i]: = temp;
end;
// Output the array
for i: integer: = 1 to n do write (a [i]: 3);

end.