My first day of computer science club.

[Falco Girgis]

Wow, I showed up half expecting some sort of semi hillbilly HTML leveled conversation. The minute I sat down, I had all sorts of math crammed up my ass.

I had to learn how to convert octal, hex, base 10, and binary numbers on just the first day. Wow, this is some pretty hardcore stuff.

We go to competition later on. There is a C programming portion and a logic exam on paper. Last year, the school won last place in nationals.

The teacher said that we're up against all of the private school preps who have thousands of dollars and carry laptops with them wherever they go... :?

This club will undoubtedly prove interesting. I'm definately going to have to be committed here....

[Wutai]

One more thing that slaughters all of your free time.

[MarauderIIC]

I know decimal -> binary -> hex -> binary -> decimal! :)
Note the lack of decimal <-> hex. Heh.

Something like this -
F = 1111, break your decimal->binary into words (4 bytes, iirc)...
Hex -> binary, just the reverse, F = 1111.
binary->decimal, powers of two. Like this

Code: Select all

CONVERT 10011001 TO DECIMAL OR YOU DIE!!
128 64 32 16 8 4 2 1
 1   0  0  1 1 0 0 1

Add
1+8+16+128 = ...
1 + 8 = 9
+ 16 = 25,
+ 128,
= (28 + 25 = 27 + 26 = 26x2+1
= 52 + 1
= 53 + 100)
= 153.
*checks* Yay, I'm right. 

Hex for bonus points
1001, 1001 hey neato, silly me, same number twice.
1001 = 9 (1 + 8), 
0x99

If you want, here's more thought process clarification
1+8+16=128 =...

1 + 8 = 9
that's an easy one. didn't come out to 10, but 9 is always easy as well

+ 16 = 25
again with the easiness. 25 is a nice number.

+ 128
here comes the toughie
break it into 100 + 28

= 28 + 25
28 from 128, 25 from the 9+16 step (color coded)

= 27 + 26
get 28 + 25 closer together, maybe i can get a nice x2

= 26x2+1
nope. but if i can't, i can just double and add one.

= 52 + 1
multiply...

= 53 + 100
add...

= 153.
done!

Edits - to hex, thought clarification, colors

[Guest]

WHAT in teh HECK is THAT? ().0

[JS Lemming]

I think knowing number conversions is a useless skill. That's what the computer is for. Boring Repetative Tasks.