shortening code pops up prob...

[ZeroPaladn]

Hey, my decimal/binary/hex program is almost complete (damn math), and im try to shorten some code. this is the code that i made to convert decimal to binary, and you have to know how to do math between binary and decimal to see how this code works. regardless, its buggy, here it is.

code:

var numin : int var binout : array 1..8 of int var num2binmath : int := 128 get numin for i : 1..8 if numin < num2binmath then binout (i) := 0 else numin := numin - num2binmath binout (i) := 1 num2binmath := num2binmath div 2 end if end for for o : 1..8 put binout (o).. end for

thanks guys

[codemage]

Your algorithm is fundamentally flawed.
Try again using this pseudo-code:

1. Let D= the number we wish to convert from decimal to binary.
2. Repeat until D=0:
a) If D is odd, put "1" in the leftmost open column, and subtract 1 from D.
b) else (D is even), put "0" in the leftmost open column.
c) Divide D by 2.
End Repeat

This is a slim algorithm, I did it in 15 lines - if you've got significantly more than that then you can still cut back.

[ZeroPaladn]

thanks alot, the old code took up about 80 lines what youve just decribed in 15. Thats what i hate about my prgramming, i can do it, but its alot of code.

[wtd]

Look for patterns. Places where you're doing repetitive work. Then let the computer do the repitition.

[ZeroPaladn]

HURRAY! fixed it! the area where it was doing the dividing, it wonly worked when it went thru that part of the for loop, so it didnt use that command when then number was smaller than was asked, so a bunch of 0's popped up. just move the calculation (num2binmath := num2binmath div 2), like so...

code:

var numin : int var binout : array 1 .. 8 of int var num2binmath : int := 128 get numin for i : 1 .. 8     if numin < num2binmath then         binout (i) := 0     else         numin := numin - num2binmath         binout (i) := 1     end if     num2binmath := num2binmath div 2 end for for o : 1 .. 8     put binout (o) .. end for

and it works. thanks wtd.

[codemage]

Here's the algorithm I described, now that you've solved it. (For reference's sake).

code:

var dec : int var bin : array 1 .. 8 of int get dec for decreasing counter : 8 .. 1     if dec mod 2 = 1 then         bin (counter) := 1         dec := dec - 1     else         bin (counter) := 0     end if     dec := dec div 2 end for for counter : 1 .. 8     put bin (counter) .. end for

[[Gandalf]]

Ah, I posted this in the other thread by mistake... Here's what I got:

code:

var inputNum : int var binaryOut : array 1 .. 8 of int := init (0, 0, 0, 0, 0, 0, 0, 0) get inputNum for count : 1 .. 8     if inputNum mod 2 = 1 then         binaryOut (count) := 1     else         binaryOut (count) := 0     end if     inputNum := inputNum div 2 end for for decreasing count : 8 .. 1     put binaryOut (count) .. end for

[ZeroPaladn]

aha... ive studied both of your subbimmisons and somethings bugging me... what the hell does mod do?

[Tony]

mod gives you a remainder of the division.

[codemage]

6 mod 2 = 0
7 mod 2 = 1

20 mod 5 = 0
23 mod 5 = 3

etc.

A very useful operator/function (depending on the language) in certain spots.

[wtd]

Who needs loops?

code:

function dec2bin (number : int) : string    if number = 0 then       result "0"    else       result (dec2bin (number div 2) + strint (number mod 2))    end if end dec2bin

[ZeroPaladn]

so tahts what it does, ive read the turing help all it says is "modulo"... whatever that is.