new files

Task/Binary-search/Ruby/binary-search-1.rb

@@ -0,0 +1,24 @@
+class Array
+  def binary_search(val, low=0, high=(length - 1))
+    return nil if high < low
+    mid = (low + high) / 2
+    case
+      when self[mid] > val then binary_search(val, low, mid-1)
+      when self[mid] < val then binary_search(val, mid+1, high)
+      else mid
+    end
+  end
+end
+
+def do_a_binary_search(val, ary, method)
+  i = ary.send(method, val)
+  if i
+    puts "found #{val} at index #{i}: #{ary[i]}"
+  else
+    puts "#{val} not found in array"
+  end
+end
+
+ary = [0,1,4,5,6,7,8,9,12,26,45,67,78,90,98,123,211,234,456,769,865,2345,3215,14345,24324]
+do_a_binary_search(45, ary, :binary_search)
+do_a_binary_search(42, ary, :binary_search)

Task/Binary-search/Ruby/binary-search-2.rb

@@ -0,0 +1,18 @@
+class Array
+  def binary_search_iterative(val)
+    low, high = 0, length - 1
+    while low <= high
+      mid = (low + high) / 2
+      case
+        when self[mid] > val then high = mid - 1
+        when self[mid] < val then low = mid + 1
+        else return mid
+      end
+    end
+    nil
+  end
+end
+
+ary = [0,1,4,5,6,7,8,9,12,26,45,67,78,90,98,123,211,234,456,769,865,2345,3215,14345,24324]
+do_a_binary_search(45, ary, :binary_search_iterative)
+do_a_binary_search(42, ary, :binary_search_iterative)