第10题: [单项选择]对n个记录的文件进行快速排序,平均执行时间为( )。 A. O(log2n) B. 0(n) C. O(nlog2n) D. 0(n2) 参考答案:C 答案解析:[解析] 本题考查快速排序的效率。就平均时间而言,快速排序效率为O(nlog2n)。在最坏的情况下,快速排序的效率降低为O(n2)。所以正确答案为C。
第28题: [单项选择]What happened to the shop in one month A. He took the watch which was worth $1 500. B. He took the camera which was worth $15 000. C. He took the necklace which was worth $15 000. 参考答案:B