问题 单项选择题

算法的时间复杂度是指( )。

A.执行算法程序所需要的时间

B.算法程序的长度

C.算法执行过程中所需要的基本运算次数

D.算法程序中的指令条数

答案

参考答案:C

解析: 本题考查算法的时间复杂度,这个知识点是重点之一,考生应该好好理解掌握。算法的时间复杂度是指执行算法所需要的计算工作量,也就是算法在执行过程中所执行的基本运算的次数,而不是指程序运行需要的时间或是程序的长度。

单项选择题
阅读理解

My cat Toto is aging,and as she ages,her body is failing her.Mentally,she seems sharp,but after nearly sixteen years,Toto’s hips are causing her obvious trouble.In fact,they make it so that she can’t use a litter box effectively.She tries to squat(蹲坐),but mostly she just pisses(撒尿)out the back end of the box.

I spent the summer working with my vet to find things to help Toto,but nothing works.Since we can’t stand the smell of cat urine in the house,two weeks ago I took drastic measures.I banished Toto outside.(She gets to come in while I work,but I put her out for 80%of the day and night.)

Because Toto now lives outside,she eats and drinks outside.I’ ve set up a heating pad on the porch.and given her own food and water area nearby.She seems perfectly content with this arrangement except when she’s out of food,or she wants to be petted.

Strangely enough,she’s been out of food a lot lately.“I think another cat is eating Toto’s food.”I told Kris when I first noticed how quickly she was going through her bowl.

“Actually,”I said a couple of days later,“maybe it’s a dog.Whoever is eating Toto’s food keeps knocking the bowl over.”

But a few days after that,I realized that the food thief probably wasn’t even a dog.Whatever the critter(动物)was,it was messy.  Every morning,Toto’s water dish was filled with mud.The food bowl was tipped over and the porch scattered with mud and debris(残渣).“I’ ll bet it’s a coon(浣熊),”I told Kris.Though we live in a residential neighborhood not far from Portland,we’ ve seen plenty of raccoons in the six years since we moved in.

Today I got to see the cat-food thievery first-hand.Turns out it’s not one raccoon-it’s a family of four.I was lucky enough to have my camera handy as they performed their daring raid:My favorite part of this video is how Toto simply sits on her heating pad and watches the raccoons eat her food.She isn’t bothered at all.

小题1:Which of the following about Toto is true?

A.She is physically sharp.

B.She is at least sixteen years old.

C.She can’t use a litter box properly.

D.She stays outside all the while recently.小题2:The underlined part in the second paragraph is closest in meaning to________.

A.drove away or forced somebody or something to leave

B.put away or stored something

C.protected somebody or something from being harmed

D.threw something away小题3:What does the writer like most about what he filmed?

A.How Toto fought against the raccoons.

B.A family of raccoons stole the food together.

C.Toto’s casual attitude toward the raccoons.

D.How the raccoons made the writer’s porch dirty.小题4:What would be the best title of the passage?

A.My Aged Cat

B.A Banished Cat

C.An Unforgettable Experience

D.The Raccoons on My Porch