uni/inf2100/pascal2100/examples/bubblesort.pas

{
 * A simple bubble sort program.  Reads integers, one per line, and prints
 * them out in sorted order.  Blows up if there are more than 49.
}
PROGRAM Sort(input, output);
    CONST
    {* Max array size. *}
    MaxElts = 50;
    TYPE 
    {* Type of the element array. *}
    IntArrType = ARRAY [1..MaxElts] OF Integer;

    VAR
    {* Indexes, exchange temp, array size. *}
    i, j, tmp, size: integer;

    {* Array of ints *}
    arr: IntArrType;

    {* Read in the integers. *}
    PROCEDURE ReadArr(VAR size: Integer; VAR a: IntArrType);
    BEGIN
        size := 1;
        WHILE NOT eof DO BEGIN
        readln(a[size]);
        IF NOT eof THEN 
            size := size + 1
        END
    END;

    BEGIN
    {* Read *}
    ReadArr(size, arr);

    {* Sort using bubble sort. *}
    FOR i := size - 1 DOWNTO 1 DO
        FOR j := 1 TO i DO 
        IF arr[j] > arr[j + 1] THEN BEGIN
            tmp := arr[j];
            arr[j] := arr[j + 1];
            arr[j + 1] := tmp;
        END;

    {* Print. *}
    FOR i := 1 TO size DO
        writeln(arr[i])
    END.