01B-5: 图灵机

Which of the following is NOT a component of a Turing machine? 以下哪项不是图灵机的组成要件？

A tape of finite length 有限长的纸带 A tape of finite length 有限长的纸带 - 正确

A finite alphabet 有限的字母表

A finite set of states 有限种状态

A head for reading and writing 读写头

01-E-5: 数组倒置

The base cases of a recursive function are degenerated cases, without which the sequence of recursive function calls would go forever.

01XC-2: FIB()：递推方程

The naive way of computing fib(n) recursively leads to a time complexity of 
直接用定义以递归的方式计算fib(n)的时间复杂度是：

 

Θ(n2)

O(2n)  正确

Θ(2n)

O(n)