adds solutions for problems 38 and 39

euler038.rb

@@ -0,0 +1,22 @@
+def pandigital?(n)
+  n.to_s.split('').map(&:to_i).sort == [1,2,3,4,5,6,7,8,9]
+end
+
+def largest_pandigital_composition_up_to(n)
+  largest_pandigital = 1
+
+  (2..n).each do |i|
+    digit_list = []
+    multiplier = 1
+    until digit_list.length >= 9
+      digit_list += (i * multiplier).to_s.split('').map(&:to_i)
+      multiplier += 1
+    end
+    number = digit_list.join('').to_i
+    if pandigital?(number)
+      largest_pandigital = number if number > largest_pandigital
+    end
+  end
+
+  largest_pandigital
+end

euler039.rb

@@ -0,0 +1,31 @@
+def is_right_triangle?(a, b, c)
+  a ** 2 + b ** 2 == c ** 2
+end
+
+def generate_triangle_sides(perimeter)
+  triangles = []
+  (1..perimeter).each do |i|
+    (i..perimeter-i).each do |j|
+      triangles << [i, j, perimeter-i-j]
+    end
+  end
+  triangles
+end
+
+def integer_right_triangle_solutions(perimeter)
+  triangles = generate_triangle_sides(perimeter)
+  triangles.select { |x| is_right_triangle?(x[0], x[1], x[2]) }
+end
+
+def p_with_max_solution_count_up_to(n)
+  max_solution_count = 0
+  p = 2
+  (3..n).each do |i|
+    solution_count = integer_right_triangle_solutions(i).count
+    if solution_count > max_solution_count
+      max_solution_count = solution_count
+      p = i
+    end
+  end
+  p
+end