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Gray Code is a number system where only 1 bit of the number changes from one number to the next number. Print the 8 bit Gray Code values of 0 to 255.
Shortest Code wins!
Start of output:
0 00000000
1 00000001
2 00000011
3 00000010
4 00000110
5 00000111
6 00000101
7 00000100
...
You only have to print the Gray Code in binary. The decimal numbers in the example are just for reference.
"%08b"%x is the same as `b.to_i(2).rjust(8,?0)
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(Note: Leading Zeros Omitted from output)
q;main(a){a--;for(q=a^(a>>1);q;)printf("%c%i",8207,q%2),q/=2;puts("");a<256?main(a+2):0;}
I use a very neat trick in this one:
It converts a decimal to gray code (base 10), then convert that to binary which will print the grey number in reverse order. But before each time I output the mirrored grey number, I print U+200F or char(8207) which is a Right-To-Left marker character which causes output to be mirrored (and on the right side of my screen). Mirroring my backwards grey number outputs, thus making them forward, proper grey numbers (At least to human eyes, to the computer they are still backwards).
Notice the numbers are different in the LTR output, they are mirrored grey numbers.
(Note: Leading Zeros Omitted from output)
unpadded
for(;$i<256;$i++)printf("%b\n",$i^$i/2);
+2 bytes for padded: replace %b with %08b.
Thanks @user63956 for reminding me of printf.
printf("%08b\n", ...) in the padded version and inline the increment: $i/2^$i++.
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Feb 16, 2017 at 5:57
printf. I already tried that increment; it should work, but it doesn´t.
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for i in range(256): print(bin(i^(i>1))[2:].zfill(8))
swap i^(i>1) to i^i/2 because python2's division operator automatically rounds down. I was just in the middle of writing an answer when xnor closed it, it came to 49 bytes.
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