Problem 32
We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once; for example, the 5-digit number, 15234, is 1 through 5 pandigital.
The product 7254 is unusual, as the identity, 39 × 186 = 7254, containing multiplicand, multiplier, and product is 1 through 9 pandigital.
Find the sum of all products whose multiplicand/multiplier/product identity can be written as a 1 through 9 pandigital.
HINT: Some products can be obtained in more than one way so be sure to only include it once in your sum.
def is_pandigital(*args, **kwargs):
#将三个数转化成String并排序
num = sorted(''.join(str(arg) for arg in args))
print num
print "kwargs = ",kwargs
try:
if kwargs['length'] and len(num) != kwargs['length']:
return False
except KeyError:
pass
for i in range(len(num)):
if str(i+1) != str(num[i]):
return False
return True
def main():
pandigitals = set()
total = 0
for multiplicand in range(1, 5000):
for multiplier in range(1, 100):
product = multiplicand * multiplier
if is_pandigital(multiplicand, multiplier, product, length=9):
pandigitals.add(product)
print sum(pandigitals)
if __name__ == "__main__":
main()