Completed Ruby Judo challenges

1_power.rb

@@ -0,0 +1,15 @@
+def power(base, exponent)
+  answer = base
+
+  if exponent == 0 # 0 exponent
+    answer = 1
+  else
+    (exponent.abs - 1).times { answer *= base }
+  end
+
+  puts exponent < 0 ? (1.0/answer) : (answer)
+end
+
+power(3, 0)
+power(3, 1)
+power(3, -3)

2_factorial.rb

@@ -0,0 +1,14 @@
+def factorial (number)
+  answer = 1
+  i = 1
+
+  while i <= 5 do
+    answer *= i
+
+    i += 1
+  end
+
+  puts answer
+end
+
+factorial(5)

3_uniques.rb

@@ -0,0 +1,11 @@
+def uniques(array)
+  unique_array = []
+
+  array.each do |item|
+    unique_array << item unless unique_array.include? item
+  end
+
+  puts unique_array
+end
+
+uniques([1, 5, "frog", 2, 1, 3, "frog"])

4_combinations.rb

@@ -0,0 +1,18 @@
+def combinations(first, second)
+  combo_array = []
+  current_word = ""
+
+  first.each do |first_val|
+    second.each do |second_val|
+      current_word += first_val
+      current_word += second_val
+
+      combo_array << current_word
+      current_word = ""
+    end
+  end
+
+  return combo_array
+end
+
+puts combinations(["on", "in"], ["to", "rope"])

5_primes.rb

@@ -0,0 +1,10 @@
+def is_prime?(number)
+  return false if number <= 1 # 1 and below are not primes
+
+  Math.sqrt(number).to_i.downto(2).each { |factor| return false if number % factor == 0 } # has a factor, is not prime
+
+  true # prime number
+end
+
+puts is_prime?(7)
+puts is_prime?(14)

6_rectancle_overlap.rb

@@ -0,0 +1,14 @@
+# assumes that coordinates given are for the bottom left and top right of each rectangle
+
+# assumes the first set of coordinates is for the lower/left most rectangle
+
+def overlap(first, second)
+  if (first[1][0] > second[0][0]) && (first[1][1] > second[0][1])
+    return "rectangles overlap"
+  else
+    return "rectangles don't overlap"
+  end
+end
+
+puts overlap( [ [0,0],[3,3] ], [ [1,1],[4,5] ] )
+puts overlap( [ [0,0],[1,4] ], [ [1,1],[3,2] ] )

counting_game.rb

@@ -0,0 +1,37 @@
+current_number = 1
+direction = true
+player = 1
+
+while current_number <= 100 do
+
+  puts "Player #{player} says: #{current_number}"
+
+  if current_number % 7 == 0
+    direction = !direction
+  elsif current_number % 11 == 0
+    if direction
+      player += 1
+    else
+      if player == 1
+        player = 10
+      else
+        player -= 1
+      end
+    end
+  end
+
+  if !(1...10).include? player
+    player = 1
+  else
+    if direction
+      player += 1
+    else
+      if player == 1
+        player = 10
+      else
+        player -= 1
+      end
+    end
+  end
+  current_number += 1
+end