Pluperfect DigitalInvariants(PPDI) Ȥ Armstrong Numbers Ҹ ֽϴ. ٷ ε,
캸 ִ Ư ֽϴ. 153 ϸ, 153 ڸ ̸, ڸ Ͽ ϸ 153 Ǵ Դϴ. ٸ 鵵 Դϴ.
PPDI ִ TeX ũθ ҽϴ. ֿ(?) ũ \fifo ... \ofif ߽̿ϴ.
\newcount\cnt \newcount\length
\def\fifo#1{\ifx\ofif#1\ofif\fi \process#1\fifo}
\def\ofif#1\fifo{\fi}
\def\ppdi#1{\cnt=0 \def\process##1{\advance\cnt by1 }
\fifo #1\ofif \length=\cnt
\def\process##1{\advance\cnt by-1 ##1^{\number\length}\ifnum\cnt>0 +\fi }
$#1 = \fifo #1\ofif$}
\ppdi ũθ ϰ \ppdi{153} ϸ 153 شϴ PPDI ϴ. ڸ 39ڸ Ǵ Դϴ. Ʒ Դϴ.
115132219018763992565095597973971522400
115132219018763992565095597973971522401
캼?