diff --git a/problem03.rb b/problem03.rb index e69de29..8c250fb 100644 --- a/problem03.rb +++ b/problem03.rb @@ -0,0 +1,19 @@ +#problem 3 largest prime factor +#break down to primes + +def big_factor(num) + iter = 2 + big_prime = 0 + + while iter <= num + if num % iter == 0 + while num % iter == 0 + num = num / iter + big_prime = iter + iter += 1 + end + end + iter += 1 + end + big_prime +end diff --git a/problem05.rb b/problem05.rb index e69de29..1c0ee76 100644 --- a/problem05.rb +++ b/problem05.rb @@ -0,0 +1,12 @@ +#problem 5 +#Euclid algorithms: lcm = (numa * numb)/gcd(numa,numb) +# gcd = num_a % num_b until = 0 + +def great_com_div(num_a, num_b) + num_a, num_b = num_b, num_a % num_b + num_b == 0 ? num_a : great_com_div(num_a, num_b) +end + +def least_com_mult(limit) + (1..limit).inject(1){|a,b| (a*b)/great_com_div(a,b)} +end \ No newline at end of file diff --git a/problem08.rb b/problem08.rb index e69de29..53b68ae 100644 --- a/problem08.rb +++ b/problem08.rb @@ -0,0 +1,34 @@ +# problem 8 +# I know there is supposed to be some magic math to solve this but cant think of it + +number = '73167176531330624919225119674426574742355349194934 +96983520312774506326239578318016984801869478851843 +85861560789112949495459501737958331952853208805511 +12540698747158523863050715693290963295227443043557 +66896648950445244523161731856403098711121722383113 +62229893423380308135336276614282806444486645238749 +30358907296290491560440772390713810515859307960866 +70172427121883998797908792274921901699720888093776 +65727333001053367881220235421809751254540594752243 +52584907711670556013604839586446706324415722155397 +53697817977846174064955149290862569321978468622482 +83972241375657056057490261407972968652414535100474 +82166370484403199890008895243450658541227588666881 +16427171479924442928230863465674813919123162824586 +17866458359124566529476545682848912883142607690042 +24219022671055626321111109370544217506941658960408 +07198403850962455444362981230987879927244284909188 +84580156166097919133875499200524063689912560717606 +05886116467109405077541002256983155200055935729725 +71636269561882670428252483600823257530420752963450'.gsub("\n","") + +def hugest_product(number) + numbers = number.split("") + max=0 + + numbers.each_index do |i| + product = numbers[i].to_i * numbers[i+1].to_i * numbers[i+2].to_i * numbers[i+3].to_i * numbers[i+4].to_i + max = product if product > max + end + max +end