l******x
发帖数: 163 | 1 上周五面的
上来问简历，很奇怪对我做的一个东西很赶兴趣，还问了一个常见的scheme
感觉是内行。。。
接着3道题
1. A game between player A and B with a dice. Each time A toss it, B has two
options: stop or continue. If B asks to stop, he will get the reward equal
to number on the face of the dice. If B asks to continue, then A toss again
and B makes new decision. The question is what is the best strategy for B so
that B can make the highest reward.
2. Sorted arrays M and N with len m and n, find intersection of them.
Then ask if m >> n, how to do i | B*****t
发帖数: 335 | 2 for problems, how many times can A toss the dice?
if infinite times, why not B stop it when A tosses a face with the largest
number? | B****t
发帖数: 1982 | 3 同问
【在 B*****t 的大作中提到】
: for problems, how many times can A toss the dice?
: if infinite times, why not B stop it when A tosses a face with the largest
: number?
| D******n
发帖数: 2836 | 4 then he can wait until 6 comes up...what is the catch?
will
B
A
【在 l******x 的大作中提到】
: 上周五面的
: 上来问简历，很奇怪对我做的一个东西很赶兴趣，还问了一个常见的scheme
: 感觉是内行。。。
: 接着3道题
: 1. A game between player A and B with a dice. Each time A toss it, B has two
: options: stop or continue. If B asks to stop, he will get the reward equal
: to number on the face of the dice. If B asks to continue, then A toss again
: and B makes new decision. The question is what is the best strategy for B so
: that B can make the highest reward.
: 2. Sorted arrays M and N with len m and n, find intersection of them.
| B*****g
发帖数: 34098 | 5 不明白，让A continue就是了，直到搞出6
will
largest
B
A
【在 l******x 的大作中提到】
: 上周五面的
: 上来问简历，很奇怪对我做的一个东西很赶兴趣，还问了一个常见的scheme
: 感觉是内行。。。
: 接着3道题
: 1. A game between player A and B with a dice. Each time A toss it, B has two
: options: stop or continue. If B asks to stop, he will get the reward equal
: to number on the face of the dice. If B asks to continue, then A toss again
: and B makes new decision. The question is what is the best strategy for B so
: that B can make the highest reward.
: 2. Sorted arrays M and N with len m and n, find intersection of them.
| l******x
发帖数: 163 | 6 I found a similar problem on the link below
http://www.americanscientist.org/issues/id.5783,y.2009,no.2,content.true,page.1,css.print/issue.aspx
The problem sets a max value on total number of tosses.
Sorry for the confusion.
【在 B*****g 的大作中提到】
: 不明白，让A continue就是了，直到搞出6
:
: will
: largest
: B
: A
| B*****t
发帖数: 335 | 7 我想题目1的意思可能是：假设A每次扔的点数是Xi(i>=1, 1<=Xi<=6), A可以一直扔下
去，B可以得到的利益时Yi=1/N*sum(Xi),问B的strategy，当N=?时，Yi为最大的值的概率最大。不过
这是一个数学问题吧！
two
equal
again
so
【在 l******x 的大作中提到】
: 上周五面的
: 上来问简历，很奇怪对我做的一个东西很赶兴趣，还问了一个常见的scheme
: 感觉是内行。。。
: 接着3道题
: 1. A game between player A and B with a dice. Each time A toss it, B has two
: options: stop or continue. If B asks to stop, he will get the reward equal
: to number on the face of the dice. If B asks to continue, then A toss again
: and B makes new decision. The question is what is the best strategy for B so
: that B can make the highest reward.
: 2. Sorted arrays M and N with len m and n, find intersection of them.
| B****t
发帖数: 1982 | 8 学习了
http://www.americanscientist.org/issues/id.5783,y.2009,no.2,content.true,page.1,css.print/issue.aspx
If you always stop with the first roll, for example, the winnable amount is
simply the expected value of a random variable that takes the values 1, 2, 3
, 4, 5, and 6 with probability 1/6 each. That is, one-sixth of the time you
will win 1, one-sixth of the time you will win 2, and so on, which yields
the expected value 1(1/6) + 2(1/6) + 3(1/6) + 4(1/6) + 5(1/6) + 6(1/6) = 7/2
. Thus if you a | d********e
发帖数: 132 | 9 请问第三道题是什么意思？没明白题意。
two
equal
again
so
【在 l******x 的大作中提到】
: 上周五面的
: 上来问简历，很奇怪对我做的一个东西很赶兴趣，还问了一个常见的scheme
: 感觉是内行。。。
: 接着3道题
: 1. A game between player A and B with a dice. Each time A toss it, B has two
: options: stop or continue. If B asks to stop, he will get the reward equal
: to number on the face of the dice. If B asks to continue, then A toss again
: and B makes new decision. The question is what is the best strategy for B so
: that B can make the highest reward.
: 2. Sorted arrays M and N with len m and n, find intersection of them.
| y**i
发帖数: 1112 | 10 这个是可以一直继续，还是只能继续一次？
two
equal
again
so
【在 l******x 的大作中提到】
: 上周五面的
: 上来问简历，很奇怪对我做的一个东西很赶兴趣，还问了一个常见的scheme
: 感觉是内行。。。
: 接着3道题
: 1. A game between player A and B with a dice. Each time A toss it, B has two
: options: stop or continue. If B asks to stop, he will get the reward equal
: to number on the face of the dice. If B asks to continue, then A toss again
: and B makes new decision. The question is what is the best strategy for B so
: that B can make the highest reward.
: 2. Sorted arrays M and N with len m and n, find intersection of them.
| | | g*******y
发帖数: 1930 | 11 写的好长啊，简单一句话，不就是个递归的思路嘛
http://www.americanscientist.org/issues/id.5783,y.2009,no.2,content.true
,page.1,css.print/issue.aspx
amount is
1, 2, 3
time you
yields
= 7/2
the
【在 B****t 的大作中提到】
: 学习了
: http://www.americanscientist.org/issues/id.5783,y.2009,no.2,content.true,page.1,css.print/issue.aspx
: If you always stop with the first roll, for example, the winnable amount is
: simply the expected value of a random variable that takes the values 1, 2, 3
: , 4, 5, and 6 with probability 1/6 each. That is, one-sixth of the time you
: will win 1, one-sixth of the time you will win 2, and so on, which yields
: the expected value 1(1/6) + 2(1/6) + 3(1/6) + 4(1/6) + 5(1/6) + 6(1/6) = 7/2
: . Thus if you a
| r****o
发帖数: 1950 | 12 Bless!
请问第2题的intersection是指什么? 是说在array M里面找到array N的元素的位置，
还是说在array M里面找到一个范围[m..n]能cover array N里面所有的数？
多谢。
two
equal
again
so
【在 l******x 的大作中提到】
: 上周五面的
: 上来问简历，很奇怪对我做的一个东西很赶兴趣，还问了一个常见的scheme
: 感觉是内行。。。
: 接着3道题
: 1. A game between player A and B with a dice. Each time A toss it, B has two
: options: stop or continue. If B asks to stop, he will get the reward equal
: to number on the face of the dice. If B asks to continue, then A toss again
: and B makes new decision. The question is what is the best strategy for B so
: that B can make the highest reward.
: 2. Sorted arrays M and N with len m and n, find intersection of them.
| o****d
发帖数: 2835 | 13 n！的结尾的0的个数
【在 d********e 的大作中提到】
: 请问第三道题是什么意思？没明白题意。
:
: two
: equal
: again
: so
| c*******n
发帖数: 112 | 14 what is the best solution for the second question. My solution require O(n +
m) in the worst case.
The last one is easy by counting how many 5 appears in n!. | k*n
发帖数: 150 | 15 just standard set intersection, I think.
【在 r****o 的大作中提到】
: Bless!
: 请问第2题的intersection是指什么? 是说在array M里面找到array N的元素的位置，
: 还是说在array M里面找到一个范围[m..n]能cover array N里面所有的数？
: 多谢。
:
: two
: equal
: again
: so
| c******n
发帖数: 91 | 16 还剩两轮时的expected reward是4(1/6) + 5(1/6) + 6(1/6) + (1/2)(3.5) = 4.25容
易理解，但还剩三轮时的expected reward是多少文中没有提。应该也在4与5之间，不
然倒数第四
轮不会停在5或6.怎么我算出来是这个5(1/6) + 6(1/6) + (1/2)(4/6 + 5/6 + 6/6) +
(1/4)(3.5) = 3.96?
http://www.americanscientist.org/issues/id.5783,y.2009,no.2,content.true
,page.1,css.print/issue.aspx
amount is
1, 2, 3
time you
yields
= 7/2
the
【在 B****t 的大作中提到】
: 学习了
: http://www.americanscientist.org/issues/id.5783,y.2009,no.2,content.true,page.1,css.print/issue.aspx
: If you always stop with the first roll, for example, the winnable amount is
: simply the expected value of a random variable that takes the values 1, 2, 3
: , 4, 5, and 6 with probability 1/6 each. That is, one-sixth of the time you
: will win 1, one-sixth of the time you will win 2, and so on, which yields
: the expected value 1(1/6) + 2(1/6) + 3(1/6) + 4(1/6) + 5(1/6) + 6(1/6) = 7/2
: . Thus if you a
|
|
