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First solution in Clear category for Power Supply by Vasily__Chibilyaev
def power_supply(network, power_plants):
cities={j for i in network for j in i}
supplied=set()
for p in power_plants:
s={p}
for i in range(power_plants[p]):
t={n1 if c==n2 else n2 for c in s for n1, n2 in network
if c==n1 and n2 not in s or c==n2 and n1 not in s}
s|=t
supplied|=s
return cities-supplied
if __name__ == '__main__':
assert power_supply([['p1', 'c1'], ['c1', 'c2']], {'p1': 1}) == set(['c2']), 'one blackout'
assert power_supply([['c0', 'c1'], ['c1', 'p1'], ['c1', 'c3'], ['p1', 'c4']], {'p1': 1}) == set(['c0', 'c3']), 'two blackout'
assert power_supply([['p1', 'c1'], ['c1', 'c2'], ['c2', 'c3']], {'p1': 3}) == set([]), 'no blackout'
assert power_supply([['c0', 'p1'], ['p1', 'c2']], {'p1': 0}) == set(['c0', 'c2']), 'weak power-plant'
assert power_supply([['p0', 'c1'], ['p0', 'c2'], ['c2', 'c3'], ['c3', 'p4'], ['p4', 'c5']], {'p0': 1, 'p4': 1}) == set([]), 'cooperation'
assert power_supply([['c0', 'p1'], ['p1', 'c2'], ['c2', 'c3'], ['c2', 'c4'], ['c4', 'c5'],
['c5', 'c6'], ['c5', 'p7']],
{'p1': 1, 'p7': 1}) == set(['c3', 'c4', 'c6']), 'complex cities 1'
assert power_supply([['p0', 'c1'], ['p0', 'c2'], ['p0', 'c3'],
['p0', 'c4'], ['c4', 'c9'], ['c4', 'c10'],
['c10', 'c11'], ['c11', 'p12'], ['c2', 'c5'],
['c2', 'c6'], ['c5', 'c7'], ['c5', 'p8']],
{'p0': 1, 'p12': 4, 'p8': 1}) == set(['c6', 'c7']), 'complex cities 2'
assert power_supply([['c1', 'c2'], ['c2', 'c3']], {}) == set(['c1', 'c2', 'c3']), 'no power plants'
assert power_supply([['p1', 'c2'], ['p1', 'c4'], ['c4', 'c3'], ['c2', 'c3']], {'p1': 1}) == set(['c3']), 'circle'
assert power_supply([['p1', 'c2'], ['p1', 'c4'], ['c2', 'c3']], {'p1': 4}) == set([]), 'more than enough'
print("Looks like you know everything. It is time for 'Check'!")
Sept. 16, 2017
