算法回鍋肉——插入排序

示例代碼純粹是爲了加深印象，選擇的目標語言有更便捷的實現方式，另外去掉了一些假設條件檢查。

#encoding:gbk

Size = 20
arr = Array.new(Size) do	#初始化待排序數組，隨機填寫元素
	rand(Size)
end

def insertion_sort(a)
	b = a.clone
	i = j = key = 0
	for j in 1...b.size
		key = b[j]
		i = j - 1
		while i >= 0 and b[i] > key	#將目標元素插入已排序的子數組，排序的主要成本發生在這裏
			b[i + 1] = b[i]
			i -= 1
		end
		b[i + 1] = key
	end
	b
end

puts arr.inspect
res = insertion_sort(arr)
puts res.inspect

輸出如下：

---------- Ruby ----------
[19, 11, 3, 6, 0, 11, 1, 6, 19, 7, 19, 3, 10, 12, 2, 1, 8, 0, 18, 7]
[0, 0, 1, 1, 2, 3, 3, 6, 6, 7, 7, 8, 10, 11, 11, 12, 18, 19, 19, 19]

Output completed (0 sec consumed) - Normal Termination