Started solving problem #33.
Added class to handle fractions operations. Added sceleton for problem
solving.
Solved problem #33. Not checked yet.
Extended fraction class with method needed for this problem solving.
Added methods to find common divisors of two numbers and to calculate
greatest common divisor of two numbers.
Solved problem #35. Not checked yet.
Solution takes nearly two minutes to calculate, it can be optimized
later for better perfomance.
Optimized solution for problem #35. Removed all primes with at least one
even digit from calculation ( one of it's permutations became even number and
so no prime).
Time decreased to ~5 seconds from 2 minutes.
Function to find primes with only odd digits moved from problem 35 solution file
to tools/prime_numbers.
Nearly completed solution for problem #37. It successfully find 10 truncatable
numbers in primes below 10^6, but it takes too long to find eleven number a
laptop. So it needs to make algorithm faster or launch on a faster CPU to
find all numbers.