IS_CAPTURE_POSSIBLE=
->b{l={}
r=p
b.split(?/).map{|s|c={}
i=0
s.chars.map{|x|n=x.to_i;c[i]=x;i+=n<1?1:n;x==?P&&r||=l[i-2]==?p||l[i]==?p}
l=c}
r}
require 'minitest/autorun'
describe :IS_CAPTURE_POSSIBLE do
it('recognizes when capture is possible') do
assert IS_CAPTURE_POSSIBLE['8/7p/6P1/8/8/8/8/8']
assert IS_CAPTURE_POSSIBLE['8/8/p7/1P6/3P3p/8/8/8']
assert IS_CAPTURE_POSSIBLE['8/2P5/8/4P1p1/2p2P2/3p4/3p1P2/8']
assert IS_CAPTURE_POSSIBLE['8/P7/8/5P2/2pp4/3P2p1/3pP3/8']
assert IS_CAPTURE_POSSIBLE['8/P7/p7/p1P1P3/1P3p2/8/1p6/8']
assert IS_CAPTURE_POSSIBLE['8/4p1P1/2P2P1P/2p1pPpp/8/6P1/pP1p4/8']
end
it('recognizes when capture is impossible') do
refute IS_CAPTURE_POSSIBLE['8/8/8/8/8/8/8/8']
refute IS_CAPTURE_POSSIBLE['8/7P/6p1/8/8/8/8/8']
refute IS_CAPTURE_POSSIBLE['8/7p/7P/8/8/8/8/8']
refute IS_CAPTURE_POSSIBLE['8/pppppppp/8/8/8/8/PPPPPPPP/8']
refute IS_CAPTURE_POSSIBLE['8/p7/8/1p6/5P2/8/8/8']
refute IS_CAPTURE_POSSIBLE['8/p7/P7/2P1p1p1/2p5/8/PP6/8']
end
end