Problem 36 - Find the sum of all numbers less than one million, which are palindromic in base 10 and base 2.

링크

The decimal number, 585 = 1001001001₂ (binary), is palindromic in both bases.

Find the sum of all numbers, less than one million, which are palindromic in base 10 and base 2.

(Please note that the palindromic number, in either base, may not include leading zeros.)

python

def binary(n): res = '' while n > 0: res += str(n % 2) n /= 2 return res def palindrom(k): b = binary(k) rb = b[::-1] return rb[0] == '1' and b == rb s = 0 for i in range(1, 999): k1 = int(str(i) + str(i)[-2::-1]) k2 = int(str(i) + str(i)[::-1]) if palindrom(k1): s += k1 if k2 < 1000000 and palindrom(k2): s += k2 print s