find min feature implementation

DIRECTORY.md

@@ -55,6 +55,7 @@
   * [Decimal To Binary](https://github.com/TheAlgorithms/Ruby/blob/master/maths/decimal_to_binary.rb)
   * [Fibonacci](https://github.com/TheAlgorithms/Ruby/blob/master/maths/fibonacci.rb)
   * [Find Max](https://github.com/TheAlgorithms/Ruby/blob/master/maths/find_max.rb)
+  * [Find Min](https://github.com/TheAlgorithms/Ruby/blob/master/maths/find_min.rb)
   * [Number Of Digits](https://github.com/TheAlgorithms/Ruby/blob/master/maths/number_of_digits.rb)
   * [Power Of Two](https://github.com/TheAlgorithms/Ruby/blob/master/maths/power_of_two.rb)
   * [Square Root](https://github.com/TheAlgorithms/Ruby/blob/master/maths/square_root.rb)

maths/find_min.rb

@@ -0,0 +1,64 @@
+# A ruby program to find min from a set of elements
+
+# This find_min method will return the min element out of the array
+def find_min(*array)
+  min = array[0]
+  array.each do |a|
+    if a <= min
+      min = a
+    end
+  end
+    "The Min of the following elements #{array} is #{min}."
+  rescue
+    "Error: Please provide number only!"
+end
+
+# Min method will return the minimum element from the set of input elements provided
+def predefined_min(*array)
+  "The Min of the following elements #{array} is #{array.min}."
+  rescue
+    "Error: Please provide number only!"
+end
+
+# Sort method will sort the elements in ascending order. First method will return the beginning element out of the array
+def predefined_sort_first_min(*array)
+  "The Min of the following elements #{array} is #{array.sort.first}."
+  rescue
+    "Error: Please provide number only!"
+end
+
+# Using find_min
+# Valid inputs
+puts find_min(11, 29, 33)
+# The Min of the following elements [11, 29, 33] is 33.
+
+puts find_min(-221, -852, -1100, -10)
+# The Min of the following elements [-221, -852, -1100, -10] is -10.
+
+# Invalid inputs
+puts find_min(5, "95", 2)
+# Error: Please provide number only!
+
+# Using predefined_min
+# Valid inputs
+puts predefined_min(51, 82, 39)
+# The Min of the following elements [51, 82, 39] is 82.
+
+puts predefined_min(-11, -51, -10, -10)
+# The Min of the following elements [-11, -51, -10, -10] is -10.
+
+# Invalid inputs
+puts predefined_min("x", 5, 95, 2)
+# Error: Please provide number only!
+
+# Using predefined_sort_first_min
+# Valid inputs
+puts predefined_sort_first_min(1, 2, 3)
+# The Min of the following elements [1, 2, 3] is 3.
+
+puts predefined_sort_first_min(-21, -52, -100, -1)
+# The Min of the following elements [-21, -52, -100, -1] is -1.
+
+# Invalid inputs
+puts predefined_sort_first_min(5, 95, 2, "a")
+# Error: Please provide number only!