Solution: Candy Splitting (Google Code Jam 2011 Qualification Round Problem C)

Cs.py

import sys

fin = file(sys.argv[1])
fout = open(sys.argv[2], 'w')
lines = fin.readlines()
tests = int(lines[0])
candys0 = [map(int, line.split()) for line in lines]
def test0(a): return not (len(a) == 1) 
candys = filter(test0, candys0)
data = []

"""
no need to separate lists into piles!
patricks summation is exclusive or (XOR).
bitwise solution is very fast indeed.
"""

def xor0(a,b): return a^b

for candy in candys:
	if (reduce(xor0, candy) == 0):
		candy.sort()
		data.append(sum(candy[1:]))
		continue
	data.append('NO')	

for i in range(len(data)):
	fout.write("Case #%s: %s\n" % (str(i+1), str(data[i])))