Factors of an integer: Difference between revisions

=={{header|BASIC}}==

{{works with|QBasic}}

This example stores the factors in a shared array (with the original number as the last element) for later retrieval.

Note that this will error out if you pass 32767 (or higher).

<lang qbasic>DECLARE SUB factor (what AS INTEGER)

REDIM SHARED factors(0) AS INTEGER

DIM i AS INTEGER, L AS INTEGER

INPUT "Gimme a number"; i

factor i

PRINT factors(0);

FOR L = 1 TO UBOUND(factors)

PRINT ","; factors(L);

NEXT

PRINT

SUB factor (what AS INTEGER)

DIM tmpint1 AS INTEGER

DIM L0 AS INTEGER, L1 AS INTEGER

REDIM tmp(0) AS INTEGER

REDIM factors(0) AS INTEGER

factors(0) = 1

FOR L0 = 2 TO what

IF (0 = (what MOD L0)) THEN

'all this REDIMing and copying can be replaced with:

'REDIM PRESERVE factors(UBOUND(factors)+1)

'in languages that support the PRESERVE keyword

REDIM tmp(UBOUND(factors)) AS INTEGER

FOR L1 = 0 TO UBOUND(factors)

tmp(L1) = factors(L1)

NEXT

REDIM factors(UBOUND(factors) + 1)

FOR L1 = 0 TO UBOUND(factors) - 1

factors(L1) = tmp(L1)

NEXT

factors(UBOUND(factors)) = L0

END IF

NEXT

END SUB</lang>

Sample outputs:

Gimme a number? 17

1 , 17

Gimme a number? 12345

1 , 3 , 5 , 15 , 823 , 2469 , 4115 , 12345

Gimme a number? 32765

1 , 5 , 6553 , 32765

Gimme a number? 32766

1 , 2 , 3 , 6 , 43 , 86 , 127 , 129 , 254 , 258 , 381 , 762 , 5461 , 10922 ,

16383 , 32766