Rich Mellor wrote, on 02/11/2010 19:53:
I was just reading that 99/100 job applicants for programming jobs
apparently cannot write a short "fizzbuzz" program when given 10
minutes to do so in an interview.
The rules are simple -
write out the values 1 to 100 on screen
If the value is divisble by 3 write 'FIZZ' after the number
If the value is divisble by 5 write 'BUZZ' after the number
If the value is divisble by 3 and 5 write 'FIZZBUZZ' after the number
My inelegant machine code program (untested) is:
Sorry - made an error when typing the 68000 assembly language in - I
hit a key which submitted the form!
start MOVEQ #-1,D1 ;Open a screen channel
LEA screen,A0
MOVEQ #2,D3
MOVEQ #1,D0
TRAP #3 ;Uses built in ROM routine to open screen
BNE.S end
MOVEQ #6,D1
MOVE.L A1,$58(A6) ; make room on maths stack for 6 bytes
MOVE.W $11A,A2
JSR (A2)
MOVE.L $58(A6),A1
MOVEQ #1,D6 ;Initial Loop value
loop MOVE.L (A6),A1
LEA 2(A1),A0
MOVE.W D6,0(A6.A1.L) ;store value on stack
MOVE.W $F2,A2
JSR (A2) ;convert number to ASCII
MOVE.W D1,D2 ; grab length of number
MOVEQ #7,D0
MOVEQ #-1,D3
TRAP #3
MOVE.L D6,D7
DIVU #3,D7
SWAP D7
CMPI.W #0,D7
BEQ.S testbuzz
LEA fizz,A1
MOVE.W $D0,A2 ; print string
JSR (A2)
testbuzz MOVE.L D6,D7
DIVU #5,D7
SWAP D7
CMPI.W #0,D7
BEQ.S nwline
LEA buzz,A1
MOVE.W $D0,A2
JSR (A2)
nwline MOVEQ #10,D1 ;Print a new line
BSR.S printchr
CMPI.B #100,D6
BEQ.S end
ADDQ.B #1,D6
BRA.S loop
end MOVEQ #0,D0
RTS
printchr MOVEQ #-1,D3
MOVEQ #5,D0
TRAP #3
MOVEQ #0,D0
RTS
screen DC.W 17
DC.B 'con_448x200a32x16',0
fizz DC.W #4
DC.B 'FIZZ'
buzz DC.W #4
DC.B 'BUZZ'
I am sure plenty can write this in SuperBASIC, but is there a simpler
solution in machine code?
sB is my limit (8-)# I would love to see Laurence Reeves' version. He
was always looking for how to reduce code. He, for instance, did a
*very* tiny Forth for the QL.
There were loads of examples in Hermes and (especially) superHermes
code. One though from his extension code springs to mind - bp_init? To
save a byte(?), instead of doing an RTS on the final extension he did a
RTN. I probably have that wrong though (8-)#
Are you lurking Lau?
Tony
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