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First solution in Clear category for Pawn Brotherhood by spowers42
def chain(l):
"""turn a list of list into a flat list"""
new_list = list()
for item in l:
new_list.extend(item)
return new_list
def attacks(pawn):
"""get attacking positions, does not filter off board moves"""
pawn = list(pawn)
rank = chr(ord(pawn[1])+1)
files = [chr(ord(pawn[0])-1), chr(ord(pawn[0])+1)]
return [f+rank for f in files]
def safe_pawns(pawns):
attacking = set(chain([attacks(p) for p in pawns]))
safe = pawns & attacking
return len(safe)
if __name__ == '__main__':
#These "asserts" using only for self-checking and not necessary for auto-testing
assert safe_pawns({"b4", "d4", "f4", "c3", "e3", "g5", "d2"}) == 6
assert safe_pawns({"b4", "c4", "d4", "e4", "f4", "g4", "e5"}) == 1
Aug. 27, 2014
