Data commit

Task/Sorting-algorithms-Selection-sort/Ruby/sorting-algorithms-selection-sort.rb

@@ -0,0 +1,55 @@
+# a relatively readable version - creates a distinct array
+
+def sequential_sort(array)
+  sorted = []
+
+  while array.any?
+    index_of_smallest_element = find_smallest_index(array) # defined below
+    sorted << array.delete_at(index_of_smallest_element)
+  end
+
+  sorted
+end
+
+def find_smallest_index(array)
+  smallest_element = array[0]
+  smallest_index = 0
+
+  array.each_with_index do |ele, idx|
+    if ele < smallest_element
+      smallest_element = ele
+      smallest_index = idx
+    end
+  end
+
+  smallest_index
+end
+
+puts "sequential_sort([9, 6, 8, 7, 5]): #{sequential_sort([9, 6, 8, 7, 5])}"
+# prints: sequential_sort([9, 6, 8, 7, 5]): [5, 6, 7, 8, 9]
+
+
+
+# more efficient version - swaps the array's elements in place
+
+def sequential_sort_with_swapping(array)
+  array.each_with_index do |element, index|
+    smallest_unsorted_element_so_far = element
+    smallest_unsorted_index_so_far = index
+
+    (index+1...array.length).each do |index_value|
+      if array[index_value] < smallest_unsorted_element_so_far
+        smallest_unsorted_element_so_far = array[index_value]
+        smallest_unsorted_index_so_far = index_value
+      end
+    end
+
+    # swap index_value-th smallest element for index_value-th element
+    array[index], array[smallest_unsorted_index_so_far] = array[smallest_unsorted_index_so_far], array[index]
+  end
+
+  array
+end
+
+puts "sequential_sort_with_swapping([7,6,5,9,8,4,3,1,2,0]): #{sequential_sort_with_swapping([7,6,5,9,8,4,3,1,2,0])}"
+# prints: sequential_sort_with_swapping([7,6,5,9,8,4,3,1,2,0]): [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]