Date: Wed, 24 Apr 1996 15:56:14 PDT
Reply-To: Melvin Klassen <KLASSEN@UVVM.UVIC.CA>
Sender: "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From: Melvin Klassen <KLASSEN@UVVM.UVIC.CA>
Subject: Re: SAS Help
Tony Gutschmidt <0002759027@MCIMAIL.COM> writes:
>I can multiply the numbers by 100 to avoid round-off errors, and I
>can go with no negative numbers but the assumption that I would never
>want a four+ number combination is incorrect. The example I gave was
>fairly simple, but there could be more than three numbers that add up
>to the total I'm looking for. I could set an arbitrary limit like 8
>which would probably cover a lot of cases, but ideally the program could
>handle any number. Again, I'd typically be looking at 30 records or less.
Maybe SAS isn't the best programming-language for this type of problem ?!
For example, the following FORTRAN program lists all combinations
of up to 6 numbers which produce the specified sum.
Given the specific sum, below, and 30 data-records, it ran in 0.2 seconds
on an IBM mainframe computer, running the same Operating System as yours,
and listed 598 combinations.
Is one-fifth of a second "fast" enough for you? :-)
Is 6 numbers enough for you? If not, just "extend" the program.
It will take longer to run, by, let's guess, a factor of 300,
but 300 times 0.2 seconds is just under 1 minute of CPU-time. No big deal.
Lines marked with 'C*' are comments/benchmarking lines, and may be omitted.
+++
C 30 data-points, taken up to 6 at a time, to total 1100.
C Note that the data is sorted into ascending-order. This is essential!
PROGRAM EIGHT
C* INTEGER LC(6)
PARAMETER (NOBS=30)
INTEGER V(NOBS)
DATA V/
* 100, 100, 100, 125, 125,
* 150, 175, 200, 250, 300,
* 300, 350, 400, 400, 425,
* 450, 500, 550, 600, 625,
* 650, 675, 700, 700, 725,
* 750, 800, 825, 850, 875/
MAGIC = 1100
C* DO 50 K=1,6
C* 50 LC(K)=0
DO 100 L1=1,NOBS
C* LC(1)=LC(1)+1
T=V(L1)
IF (T .EQ. MAGIC) WRITE(*,*) V(L1)
IF (T .GT. MAGIC) GOTO 101
DO 200 L2=(L1+1),NOBS
C* LC(2)=LC(2)+1
T=V(L1)+V(L2)
IF (T .EQ. MAGIC) WRITE(*,*) V(L1),V(L2)
IF (T .GT. MAGIC) GOTO 201
DO 300 L3=(L2+1),NOBS
C* LC(3)=LC(3)+1
T=V(L1)+V(L2)+V(L3)
IF (T .EQ. MAGIC) WRITE(*,*) V(L1),V(L2),V(L3)
IF (T .GT. MAGIC) GOTO 301
DO 400 L4=(L3+1),NOBS
C* LC(4)=LC(4)+1
T=V(L1)+V(L2)+V(L3)+V(L4)
IF (T .EQ. MAGIC) WRITE(*,*) V(L1),V(L2),V(L3),V(L4)
IF (T .GT. MAGIC) GOTO 401
DO 500 L5=(L4+1),NOBS
C* LC(5)=LC(5)+1
T=V(L1)+V(L2)+V(L3)+V(L4)+V(L5)
IF (T .EQ. MAGIC) WRITE(*,*) V(L1),V(L2),V(L3),V(L4),V(L5)
IF (T .GT. MAGIC) GOTO 501
DO 600 L6=(L5+1),NOBS
C* LC(6)=LC(6)+1
T=V(L1)+V(L2)+V(L3)+V(L4)+V(L5)+V(L6)
IF (T .EQ. MAGIC) WRITE(*,*) V(L1),V(L2),V(L3),V(L4),V(L5),V(L6)
IF (T .GT. MAGIC) GOTO 601
600 CONTINUE
601 CONTINUE
500 CONTINUE
501 CONTINUE
400 CONTINUE
401 CONTINUE
300 CONTINUE
301 CONTINUE
200 CONTINUE
201 CONTINUE
100 CONTINUE
101 CONTINUE
C* WRITE (*,*) LC
END
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