Code Golf: Decision Tree
In Google Code Jam 2009, Round 1B, there is a problem called Decision Tree that lent itself to rather creative solutions.
Post your shortest solution; I'll update the Accepted Answer to the current shortest entry on a semi-frequent basis, assuming you didn't just create a new language just to solve this problem. :-P
Current rankings:
- 107 Perl
- 121 PostScript (binary)
- 132 Ruby
- 154 Arc
- 160 PostScript (ASCII85)
- 170 PostScript
- 192 Python
- 196 JavaScript
- 199 Common Lisp
- 212 LilyPond
- 273 Scheme
- 280 R
- 281 sed w/ bc
- 312 Haskell
- 314 PHP
- 339 m4 w/ bc
- 346 C
- 381 Fortran
- 462 Java
- 718 OCaml
- 759 F#
- 1554 sed
- C++ not qualified for now
Answer
sed in 1554 chars (pure) / 281 (with bc)
Yes, seriously.
Usage: sed -r -f thisfile.sed < input.in > output.out
(works on GNU sed)
1d
/ /!{x
s/^$/Case #Y:/
:i
s/9Y/Y0/
ti
s/#Y/#0Y/
s/:/:0123456789/
s/(.)Y(.*):[0-9]*\1(.).*/\3\2Y:/
x
G
s/.*\n|Y//gp
z
:p
N
/[()]/s/ |\n//g
y/()/JK/
tp
H
d}
G
s/\n[^J]*/ %/
s/[^JK]*$//
:c
s/J1?([.-9]+)(.*)K/\2@\1/
/%@/by
:b
/J/s/T//
s/J([^JK]*)K/TC\1B/
tb
/ (.+) .*%\1C/{s/%[^C]*/%/
s/T.*B//
by}
s/%.*T/%/
:y
y/CB/JK/
tc
s/.\.0*\b//g
:r
/@.*@/{s/\w*@\w*$/C&B/
s/C(\w)(.*B)/\1C\2~/
s/"[^"]*/&0/g
:t
s/(\w)(C.*)(\w)B(.*~)/\1\2B\3\4\1\3/
T
s/~(10|2[01]|3[0-2]|4[0-3]|5[0-4]|6[0-5]|7[0-6]|8[0-7]|9.)/&Q/
s/(.)(.)Q/\2\1/
s/~0\w/`00/
s/~1\B/`0/
s/~22/`04/
s/~23/`06/
s/~24/`08/
s/~33/`09/
s/~25/`10/
s/~26|~34/`12/
s/~27/`14/
s/~28|~44/`16/
s/~29|~36/`18/
s/~35/`15/
s/~45/`20/
s/~37/`21/
s/~38|~46/`24/
s/~55/`25/
s/~39/`27/
s/~47/`28/
s/~56/`30/
s/~48/`32/
s/~57/`35/
s/~49|~66/`36/
s/~58/`40/
s/~67/`42/
s/~59/`45/
s/~68/`48/
s/~77/`49/
s/~69/`54/
s/~78/`56/
s/~79/`63/
s/~88/`64/
s/~89/`72/
s/~99/`81/
s/`(.)(.)/~\1'\2/
bt
:
s/(~.)'/\1/
s/..'/K&/
/K/bk
:v
s/=(,?.)'/\1/
s/,/1'/
t
s/B(.*)~/\1B"/
tr
s/"(\w*)0/A\1/g
/A.*A/{s/A[^A]*$/J&K/
:k
s/([^A])(J.*)([^A])K/\2K\1\3/
s/K(10|2[01]|3[0-2]|4[0-3]|5[0-4]|6[0-5]|7[0-6]|8[^9]|9.)/&Q/
s/(.)(.)Q/\2\1/
s/K0/=/
s/K11/=2/
s/K12/=3/
s/K13|K22/=4/
s/K14|K23/=5/
s/K15|K24|K33/=6/
s/K16|K25|K34/=7/
s/K(17|26|35|44)/=8/
s/K(18|27|36|45)/=9/
s/K(19|28|37|46|55)/W0/
s/K(29|38|47|56)/W1/
s/K(39|48|57|66)/W2/
s/K49|K58|K67/W3/
s/K59|K68|K77/W4/
s/K69|K78/W5/
s/K79|K88/W6/
s/K89/W7/
s/K99/W8/
s/W/=,/
/'/bv
s/\b=/K:/
tk
s/[:JK]A?//g
s/,/,0123456789GF/
s/(.),.*\1(.).*F/\2/
s/G/,0/
tk}
/A.*A/bv}
s/\w*C.*A//
tr
s/.*@/./
This solution omits the leading zero in front of the decimal point, and does not handle cases where the answer is 1.00. Luckily, the GCJ judge accepts the lack of a zero, and does not have any cases where the answer is 1.00.
To include the leading zero, change the last line to s/.*@/0./; and to handle a 1.00 case, append the line s/^$/1/.
Here's a solution that outsources the multiplication to bc:
1d
/ /!{x
s/\n.*//
s/.*/echo 0&+1|bc/e
x
g
s/.*/Case #&:/p
:p
N
/[()]/s/ |\n//g
y/()/JK/
tp
H
d}
G
s/\n[^J]*/ %/
s/[^JK]*$//
:c
s/J([.-9]+)(.*)K/\2*\1/
/%\*/s/.*%.(.*)/echo \1|bc -l/e
:b
/J/s/T//
s/J([^JK]*)K/TC\1B/
tb
/ (.+) .*%\1C/{s/%[^C]*/%/
s/T.*B//
b}
s/%.*T/%/
:
y/CB/JK/
tc