def parse_line(line_str)
line = {}
i = 0
line_str.chars.each do |c|
case c
when '1'..'8'
i += c.to_i
else
line[i] = c
i += 1
end
end
line
end
def is_capture_possible(board)
last_line = {}
board.split('/').each do |line_str|
line = parse_line line_str
return true if (0..8).any?{ |i| last_line[i] == 'p' && (line[i-1] == 'P' || line[i+1] == 'P') }
last_line = line
end
false
end
require 'minitest/autorun'
describe :parse_line do
it('parses empty lines') { parse_line('8').must_equal({}) }
it('recognizes pawns at correct indices') do
parse_line('7p').must_equal({ 7 => 'p' })
parse_line('2p2P2').must_equal({ 2 => 'p', 5 => 'P' })
parse_line('pP1p4').must_equal({ 0 => 'p', 1 => 'P', 3 => 'p' })
end
end
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