lesson5

Quick_Sorting.py

+'''
+
+目标:实现快速排序
+
+概念:
+	从列表中任意选一个元素作为基准
+	然后将所有比基准小的数都放到它的左边
+	将所有比基准大的数都放到它的右边
+	对左边和右边的元素集不断重复上面的操作
+	直到排序完成
+'''
+import random
+
+def qsort(List):
+	if len(List)>=2:
+		base = random.choice(List)
+		left_base = []
+		right_base = []
+		equal = []
+		for num in range(len(List)):
+			if List[num]<base:
+				left_base.append(List[num])
+			elif List[num]>base:
+				right_base.append(List[num])
+			else:
+				equal.append(List[num])
+
+		return qsort(left_base)+equal+qsort(right_base)
+	else:
+		return List
+
+if __name__ == '__main__':
+
+	List = [[2],[2,6,3,7,9,1,5],[2,2,6,6,3,8,1,9]]
+	for i in List:
+		try:
+			result = qsort(i)
+			print(result)
+			print("排序成功\n")
+		except:
+			print("排序失败")
+