For each function f(n) and time t in the following table, determine the largest size n of a problem that can be solved in time t, assuming that the algorithm to solve the problem takes f(n)
| 1 second | 1 minute | 1 hour | 1 day | 1 month | 1 year | 1 century |
lg n |
|
|
|
|
|
|
|
sqrt(n) |
|
|
|
|
|
|
|
n |
|
|
|
|
|
|
|
n lg n |
|
|
|
|
|
|
|
n2 |
|
|
|
|
|
|
|
n3 |
|
|
|
|
|
|
|
2n |
|
|
|
|
|
|
|
n! |
|
|
|
|
|
|
|
这个问题看起来很简单,不过很久不碰数学分析的我,已经忘了其中几个式子的解法:
nlgn <= time的话,n的最大值是多少? 没有精确解,不过似乎可以用逼近法算出近似值,那么这个逼近法的算法是什么呢?
同样的问题对于 n! 呢?