Lua的排序算法——快速排序

a = {1,3,5,2,6,8,10,3,6,20}

--快速排序(以數組最左邊的值爲基準，比它小的放左邊，比它大的放右邊，然後再對左右兩邊的數組進行同樣的操作，直到細分排列完成)
local function KuaiSuPaiXu(arr, startIndex, endIndex)
	if startIndex >= endIndex then
		return
	end
	local lowIndex = startIndex
	local highIndex = endIndex
	local key = arr[lowIndex]
	while(lowIndex < highIndex) do
		while(arr[highIndex] >= key and highIndex > lowIndex) do --找到一個小於key的值放在左邊
			highIndex = highIndex - 1
		end
		arr[lowIndex] = arr[highIndex]
		while(arr[lowIndex] <= key and highIndex > lowIndex) do --找到一個大於Key的放在右邊
			lowIndex = lowIndex + 1
		end
		arr[highIndex] = arr[lowIndex]
		arr[lowIndex] = key --把key放在遊標停止處
	end
	--對數組整體做一次排序，得到中間索引，切分成左右兩個數組，然後再遞歸
	KuaiSuPaiXu(arr, startIndex, lowIndex - 1)
	KuaiSuPaiXu(arr, lowIndex + 1, endIndex)
end

local function PrintTab(t)
	for k, v in pairs(t) do
		print(v)
	end
end

print("KuaiSuPaiXu")
KuaiSuPaiXu(a, 1, #a)
PrintTab(a)