I wrote this back in October of 1994 when the idea of an IOTCC (International Obfuscated Tcl Code Contest) was first suggested, but since the contest has never materialized, I've decided to go ahead and publish my entry.
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@0)(*@# 87\32kj\\h df8 jvm*f &^t-c-l{:>? ~``akj'<f sdf} \236+|,3+!~=%@^%
r\145n\141\155\145 \162\e\156a\155e @y{!;@\y{\! \146\o\162\ma\164 ~&z
[~&z @%c\{! 121] p\162\157\c \%2\d;\@\y\173! f\157\162 4;\100y\173\! [
\~\&z %s{\! @\y] f(x);f(x) \~&\z p\1362
f\50x) [p\^2 g\%c\o\45\s 108 ba\l ] g%c ;[\p\^\062 f\%c\x\051 \
40 ] s\e\164 +|q;+\174q #j& \160\^2;f(x\) [${#j&} %\143n%s\162 \
105 \c ] b`= ;# 8&dfjlw {f98df 3% *} ()~X &Yh<": [jP |`~! x4& Zj8t
\+|\161 z34$ [\p\136\62 n%s\li [[\53\174q #\j\& ] \157%c\e\167 \
110]]\156e ; \%2d ^\x$` \ { \g\%\c '<:;4 {\53\174\161 \77 \062} {
${?} <[ \+|q '<:]} {b`= ?} { g\45c '${?}; +\174q '[ +|\161 ?] 1 }}
\146\50\x\51 f(x\) @\+/ ;+|q '<: 100;^x$` ;@\53/ +|q i*T#; i*T# \
`%(- 0; @\+/ ex\160\162 E)~'; i\52T# \F\d [${#j&} \s\164d\%c\45\s\
\06111 \ut]; \100\53\57 \160\u\164s p\>+; 4 i*T#\ i\Y\&\^x\ \062 {
[i*\T# iY&^x ]<${'<:}} { b`= i\Y&^x } { i[\p\1362 %c 102] [i*T#\
'[\151\*\T\# i\131\46^x]] {p>+ -${z34$} [
p^2 \ %5d [i*T# iY&^x]]; b`= `%(-;[p^2 i]f { [E)~' [i*T# `%(-]%12]==0} {
\160>+ "" } ;[E)~' 8/2] {i*T# j [E)~' 2*[i*\T# iY\&^\x]]} {$j < ${'<:}}\
{i*T# j [E\51~\47 $j+${iY&^x}] } { i*T# '$j 0} } }; \i\146 { [E\)\176' [
i\*T\# `%(-]%12]!=[\105)\176' t\141n(0\51]} {p\>\53 \0 };\145\170i\164 0
Can you figure out what it does?
An explanation will be coming soon...
You can also download a copy of the program and try it out.