单选题：Hiring Problem Revisit
Consider the hiring problem. Assume that the $$n$$ candidates arrive in random order, and that no two candidates have the same performance. Let $$k$$ be some fixed parameter in the range $$[1, n]$$. We use the following algorithm.
interview the first k candidates, but hire none of them
for candidates i = k+1 to n
if candidate i is better than all the first k candidates
hire candidate i
How many candidtes will be hired in expectation?
A.$$ln \frac{n}{k}$$
B.$$(n-k)/(k+1)$$
C.$$ln(n-k)$$
D.$$n/e$$
答案：B
interview the first k candidates, but hire none of them
for candidates i = k+1 to n
if candidate i is better than all the first k candidates
hire candidate i
How many candidtes will be hired in expectation?
A.$$ln \frac{n}{k}$$
B.$$(n-k)/(k+1)$$
C.$$ln(n-k)$$
D.$$n/e$$
答案：B