Challenge: Validate a code

[Agamemnus]

My entry. Uses longs! I know, BAD!

Code:

'Is this BLITZTASTIC OR WHAT??!?!?

DECLARE FUNCTION validate.all% (file1$)
DECLARE FUNCTION num.exists% (n&)
DECLARE SUB load.valid.nums (file1$)
DIM SHARED num.max AS LONG, num.max2 AS LONG: num.max = 100000: num.max2 = num.max \ 16
DIM SHARED huge.array(1 TO num.max2) AS LONG
DIM SHARED bit2(0 TO 15) AS LONG
DIM SHARED num.amount AS INTEGER: num.amount = 20000
FOR I% = 0 TO 15: bit2(I%) = 2 ^ I%: NEXT I%

CLS

'OPEN "valid.txt" FOR OUTPUT AS #1
'FOR I% = 1 TO 20000
'a$ = LTRIM$(STR$(INT(RND * 100000)))
'PRINT #1, a$
'NEXT I%
'CLOSE
'SYSTEM

load.valid.nums ("valid.txt")

t1# = TIMER
PRINT validate.all%("valid.txt")
t2# = TIMER: PRINT "Time for"; num.amount; "values to be processed:"; t2# - t1#; "seconds."

'use num.exists%(n&) for individual numbers..
DO
INPUT n&
IF n& > 99999 THEN PRINT "Number bigger than 99999..."
IF n& < 0 THEN PRINT "Number smaller than 0..."
IF num.exists%(n&) THEN PRINT "Number exists!" ELSE PRINT "Number doesn't exist.."
LOOP

SUB load.valid.nums (file1$)
enter.char$ = CHR$(13): a1$ = " ": a2$ = "  ": num1$ = "": num2% = 0
OPEN file1$ FOR BINARY AS #1
j% = 1: FOR I% = 1 TO num.amount
num1$ = ""
GET #1, , a1$: IF a1$ = enter.char$ THEN GOTO v2
IF INSTR("0123456789", a1$) = 0 THEN GET #1, , a1$: GOTO v2
FOR j% = 1 TO 4
num1$ = num1$ + a1$
GET #1, , a1$: IF a1$ = enter.char$ THEN GOTO v1
IF INSTR("0123456789", a1$) = 0 THEN GET #1, , a1$: GOTO v2
NEXT j%
num1$ = num1$ + a1$
GET #1, , a1$
v1: IF a1$ <> enter.char$ THEN GET #1, , a1$: GOTO v2
num2& = VAL(num1$)
k% = num2& MOD 16
j% = num2& \ 16 + 1
temp& = huge.array(j%)
IF (temp& AND bit2(k%)) = 0 THEN huge.array(j%) = temp& + bit2(k%)
v2: GET #1, , a1$
NEXT I%
CLOSE
END SUB

FUNCTION num.exists% (n&)
k% = n& MOD 16
j% = n& \ 16 + 1
IF (huge.array(j%) AND bit2(k%)) THEN num.exists% = -1
END FUNCTION

FUNCTION validate.all% (file1$)
is.valid% = -1
enter.char$ = CHR$(13): a1$ = " ": a2$ = "  ": num1$ = "": num2% = 0
OPEN file1$ FOR BINARY AS #1
j% = 1: FOR I% = 1 TO num.amount
num1$ = ""
GET #1, , a1$: IF a1$ = enter.char$ THEN GOTO v2b
IF INSTR("0123456789", a1$) = 0 THEN GET #1, , a1$: GOTO v2b
FOR j% = 1 TO 4
num1$ = num1$ + a1$
GET #1, , a1$: IF a1$ = enter.char$ THEN GOTO v1b
IF INSTR("0123456789", a1$) = 0 THEN GET #1, , a1$: GOTO v2b
NEXT j%
num1$ = num1$ + a1$
GET #1, , a1$
v1b: IF a1$ <> enter.char$ THEN GET #1, , a1$: GOTO v2b
num2& = VAL(num1$)
k% = num2& MOD 16
j% = num2& \ 16 + 1
temp& = huge.array(j%)
IF (temp& AND bit2(k%)) = 0 THEN is.valid% = 0
v2b: GET #1, , a1$
NEXT I%
CLOSE
validate.all% = is.valid%
END FUNCTION