def lychrel(number):
count = 0
a = reverse_and_add(number)
if is_palindrome(a):
return False
while count < 50 and not is_palindrome(a):
a = reverse_and_add(a)
if is_palindrome(a):
return False
count += 1
return True
def compute(limit):
"""Finds the largest palindrome made from multiplying 2 numbers whose max sizes are limit."""
for i in range(100, limit):
for j in range(100, limit):
# Cache product
result = i * j
if is_palindrome(result):
yield result
def is_lychrel(n):
for i in range(1, 50):
#if n % 10 == 0:
# return False
n += reverse_number(n)
if is_palindrome(n):
return False
return True
def is_lychrel_number(num, iterations=0):
if num in lychrel_numbers:
return lychrel_numbers[num]
new_num = num + reverse(num)
if is_palindrome(new_num):
is_lychrel = False
elif iterations >= 50:
is_lychrel = True
else:
is_lychrel = is_lychrel_number(new_num, iterations + 1)
if num < 10000:
lychrel_numbers[num] = is_lychrel
return is_lychrel
def problem04():
"""
Q: Find the largest palindrome made from the product of two 3-digit numbers.
A: 906609
"""
largest = 0
for num in range(900, 999):
for n in range(900, 999):
product = num*n
if product < largest:
continue
if helpers.is_palindrome(product):
largest = product
return largest
def get_palindromic_digits(number_of_digits):
"""Get all palindromes from the product of two n digit numbers
"""
hundreds = int('1' + number_of_digits * '0')
all_digits = [x for x in range(hundreds)]
number_list = list(
filter(lambda x: len(str(x)) == number_of_digits, all_digits))
palindromes = {}
for each in number_list:
remove_each = set(number_list) - set([each])
for every in remove_each:
number = each * every
if is_palindrome(str(number)) == True:
palindromes[number] = [each, every]
return palindromes
#!env/bin/python
import helpers as h
res = 0
for x in range(1,1000000,2):
if h.is_palindrome(x):
if h.is_palindrome(h.str_base(x,2)):
print "B10: {}\tB2: {}".format(x,h.str_base(x,2))
res += x
print res
def compute(limit):
for i in range(limit):
if is_palindrome(i) and is_palindrome(bin(i)[2:]):
yield i
def is_dual_palindrome(n):
return is_palindrome(n) and is_palindrome(bin(n).lstrip('0b'))
from helpers import get_binary_value, is_palindrome
total = 0
for x in range(1, 10**6, 2):
if is_palindrome(x) and is_palindrome(get_binary_value(x)):
total += x
print(total)
#
highest_result = 0
for x in range(100, 1000):
for y in range(100, 1000):
product = x * y
if str(product) == str(product)[::-1] and product > highest_result:
highest_result = product
print(x, y, highest_result)
print(highest_result)
#
#
# highest_result = 0
# for x in range(100, 1000):
# for y in range(x, 1000):
# highest_result = max(highest_result, is_palindrome(x * y))
#
# print(highest_result)
#
#
# print(sorted([x * y for x in range(100, 1000) for y in range(x, 1000) if str(x*y) == str(x*y)[::-1]])[-1])
for x in range(999, 100, -1):
for y in range(x, 1000):
if is_palindrome(x * y):
print(x, y, x * y)
break
else:
continue
break