迭代
请使用迭代查找一个list中最小和最大值,并返回一个tuple:
def findMinAndMax(L): if L==[]: return None,None if len(L)==1: return L[0],L[0] min=max=L[0] for n in L[1:]: if max<n: max=n elif min>n: min=n return min,max # 测试 if findMinAndMax([]) != (None, None): print('测试失败!') elif findMinAndMax([7]) != (7, 7): print('测试失败!') elif findMinAndMax([7, 1]) != (1, 7): print('测试失败!') elif findMinAndMax([7, 1, 3, 9, 5]) != (1, 9): print('测试失败!') else: print('测试成功!')