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Posted: Sun Jul 25, 2010 3:50 pm
by 0042
...math was never my best subject... *holds head*
I DID look at wikipedia. I can't figure out how to convert it myself though, and found a hex/binary/etc converter online. But I tried typing 233 into the 'regular number' area and I got 3 sets of digits in the Hex box!! and what looked to be far too many strings of numbers in the Dec box.
What am I doing wrong? Is it my approach?
Posted: Sun Jul 25, 2010 5:34 pm
by CodeX
Was that number 563? That's 0x233 in decimal...
You can convert numbers using basic calculations and rounding down which is easy enough on a handy calculator. Here's a function that will get you the nᵗʰ digit of a number with any radix you do:
Code: Select all
digit(value, number, radix) :=
floor(value % (radix ^ number)) / (radix ^ (number - 1))
floor(x) is just rounding down and is equivalent to round(x - 0.5), % is the modulo operation (modulus in americanish) which is equal to the remainder of division of the two operands e.g. 9 % 8 = 1.
is the same as
for hexadecimal the radix is 16. You can work out quickly in advance how many digits there will be from
where ceil(x) is rounding up and equivalent to round(x + 0.5), if you don't have log (logarithms) available you just do a loop until
radix ^ number is bigger than
value. Here's an example in Python:
Code: Select all
# this doesn't work with values less than 0
def convert(value,radix):
digits = [] # where the digit values go
digit = 1 # get ready for first one
x = 0 # start at 0 to
while x <= value: # Do this loop while radix ^ digit is less than value
x = radix ** digit # x = radix ^ digit
v = int((value % x) / (radix ** (digit - 1))) # value of digit
digits = [v] + digits # put the current value of digit on list
digit = digit + 1 # get ready to work out next digit
return digits
print convert(2333,16)
print convert(0,16)
print convert(256,16)
print convert(16,16)
this code prints
[9, 1, 13]
[0]
[1, 0, 0]
[1, 0]
so hex versions would be 0x91d, 0x0, 0x100 and 0x10.
simples! If you find this hard to understand consider it a part of the challenge.
Posted: Sat Jul 31, 2010 8:57 pm
by 0042
Thanks CodeX! I'll take another look at it when I'm more awake.
Posted: Fri Oct 08, 2010 12:12 am
by Bliss
I solved it without using hex values. Everybody did the first step right that is to convert the 3 numbers into bytes. The second step isn't difficult , but not everyone will think of it.
Think Bits.
Posted: Sat Jul 16, 2011 10:48 pm
by Sairera
I turned the decimals into 8 bit integers and got this:
199=11000111
77=1001101
202=11001010
But can someone please explain to me how to turn those into a 24 bit unsigned integer? I wasn't able to find a reliable explanation online. Thanks!
-しあ
Posted: Sun Jul 17, 2011 8:55 pm
by laz0r
PM'ed to you
Posted: Fri Oct 28, 2011 4:23 am
by bemyfriend4397
all with genius mind accept me... 