wb =. 'white',:'black'

dist =. [: %: +/@:*:@+.@(-&50j50)
clamp =. ((o. 2)&+)^:(<&0)
angle =. [: clamp (o. 0.5) - 12 o. (-&50j50)

solve =. inradius`('white'"_)@.(dist@] > 50"_)
inradius =. otherwise`(wb {~ 0 < [)@.((50 = [ *. 50 <: ])/@+.@])
otherwise =. wb {~ (angle % o.@2:)@] <: %&100@[

join =. ([,LF,])/

NB. Drop head because we don't need the number of cases
cases =. >@}.@(-.&a:)@(e.&(CR,LF) <@".;._2 ])

format =. [: , ,&': '@('Case #'&,)@":"0@>:@i.@# ,. (,&LF)"1

in =. 1!:1 <'progress_pie.txt'
out =. format ({. solve j./@}.)"1 cases in
out 1!:2 <'progress_pie_out.txt'

exit''