Create insertion_sort.rb (#1222)

* Create insertion_sort.rb

* Update insertion_sort.rb

* Update insertion_sort.rb

* Update insertion_sort.rb

codes/ruby/chapter_sorting/insertion_sort.rb

@@ -0,0 +1,26 @@
+=begin
+File: insertion_sort.rb
+Created Time: 2024-04-02
+Author: Cy (3739004@gmail.com), Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
+=end
+
+### 插入排序 ###
+def insertion_sort(nums)
+  n = nums.length
+  # 外循环：已排序区间为 [0, i-1]
+  for i in 1...n
+    base = nums[i]
+    j = i - 1
+    # 内循环：将 base 插入到已排序区间 [0, i-1] 中的正确位置
+    while j >= 0 && nums[j] > base
+      nums[j + 1] = nums[j] # 将 nums[j] 向右移动一位
+      j -= 1
+    end
+    nums[j + 1] = base # 将 base 赋值到正确位置
+  end
+end
+
+### Driver Code ###
+nums = [4, 1, 3, 1, 5, 2]
+insertion_sort(nums)
+puts "插入排序完成后 nums = #{nums}"