Wednesday, February 23, 2011

Project Euler–Problem 8

Description

From Project Euler:
Find the greatest product of five consecutive digits in the 1000-digit number.
73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450

Tuesday, February 22, 2011

Project Euler–Problem 7

Description

From Project Euler:
By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.
What is the 10001st prime number?

Saturday, February 19, 2011

Project Euler–Problem 6

Description

From Project Euler:
The sum of the squares of the first ten natural numbers is,
12 + 22 + ... + 102 = 385
The square of the sum of the first ten natural numbers is,
(1 + 2 + ... + 10)2 = 552 = 3025
Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025 - 385 = 2640.
Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

Friday, February 18, 2011

Project Euler–Problem 5

Description

From Project Euler:
2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.
What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?

Thursday, February 17, 2011

Project Euler–Problem 4

Description

From Project Euler:
A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 x 99.
Find the largest palindrome made from the product of two 3-digit numbers.

Wednesday, February 16, 2011

Project Euler–Problem 3

Description

From Project Euler:
The prime factors of 13,195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600,851,475,143?

Project Euler–Problem 2

Description

From Project Euler:
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
1, 2, 3, 5, 8, 13, 21, 34, 55, 89, …
By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even valued terms.

Wednesday, February 2, 2011

Project Euler–Problem 1

In my constant effort to learn more, I’ve run into  a number of road blocks with my progression with YABE. Why? Because I’m trying to write my blog engine in Ruby on Rails, while I have little real experience with Ruby, Rails, RSpec, Gems, etc. etc. So I am trying to rectify this by at least getting the basics of the “Ruby way” down. My solution? Well simple really. I am going to go through and start implementing the problems from Project Euler in Ruby and testing my solutions using RSpec. I’ve already completed a few of the problems, which you can see here