problem-036.py

### Problem 36 - Double-Base Palindromes
###-------------------------------------------------------------------------------------------------
### 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.)

### Solution

# Function to convert to binary. n:int -> string
def convertToBinary(n):
    binary = []

    if n == 0:
        return [0]

    while n != 0:
        binary.append(n % 2)
        n //= 2

    binary = "".join([str(i) for i in binary])
    return binary[::-1]


# Function to determine if palindrome. n:string -> boolean
def isPalindrome(n):
    if n == n[::-1]:
        return True
    else:
        return False


# Find sum of palindromes in base 2 and 10 below 1000000
sumOfPalindromes = 0
for i in range(1, 1000000):
    if isPalindrome(str(i)) and isPalindrome(convertToBinary(i)):
        sumOfPalindromes += i

print(
    "The sum of palindromes in base 2 and 10 below 1,000,000 is: "
    + str(sumOfPalindromes)
)