$\exists\:$ another solution $\:\big|\:$ Someone shall present it.
"It is better to solve one problem five different
ways, than to solve five problems one way."
George Pólya (1887 - 1985)
$\exists\:$ something $\:\big|\:$ I've overlooked it.
"The Art of being wise is the Art of knowing what to overlook."
William James (1842 - 1910)
An answer of mine, regarding Kaprekar's constant $6174$
Quite happy with it, despite still being incomplete.
( This profile is written for math.SE, but Stack Exchange plainly copies it over to other sites.
$\;$ Where it makes less sense. )