h********2
发帖数: 23 | 1 Below are still questions from Blook's 合集s, the questions I feel
unsufficently discussed. They either has the good answers that is not
sufficiently explained, or suspicious answers, or no answer. If you think
you has good understanding of these questions, please do discuss them in a
bit more details.
Be our hero and tutor on them, yes, I mean you, do it now! Please always
mention the numbering of problem you are discussing.
☆─────────────────────────────────────☆
Question 1.
A deck of cards with | h********2
发帖数: 23 | 2 ☆─────────────────────────────────────☆
Question 5.
A n*m matrix is composed of n*m unit cubes. Draw a diagonal line connecting
two opposite corners of matrix, develop a formula showing how many cubes are
crossed(touch on corner does not count as cross) by the diagonal line are
any n and m.
A: n+m-gcf(n,m), with gcf the greatest common factor. | f*******g
发帖数: 79 | 3 Q1:
Card N 一定在右手, 贡献1
Card N-1 是否在右手,取决于它先于Card N还是后于Card N, 机会相等故贡献 1/2.
card N-2 是否在右手,取决于它在 它在N 和 N-1 之前,不计 N 与 N-1先后顺序所以机
会是 1/3.
以此类推,所有牌对expectation value 的贡献是:
1+1/2+1/3+...+1/N | f****e
发帖数: 590 | 4 Question 1
这里E[N]是指随机抽取N张牌后，手里所剩牌的的期望值(不必理会stop when you get
card N,因为继续抽下去手里的牌数也不会变）
那么E[N-1]就是你随机抽出N-1张手里的牌数的期望值
只有当card N是最后一张的时候这两个才会有区别，所以解答里那个方程体现了两者的
关系
─☆
【在 h********2 的大作中提到】
: Below are still questions from Blook's 合集s, the questions I feel
: unsufficently discussed. They either has the good answers that is not
: sufficiently explained, or suspicious answers, or no answer. If you think
: you has good understanding of these questions, please do discuss them in a
: bit more details.
: Be our hero and tutor on them, yes, I mean you, do it now! Please always
: mention the numbering of problem you are discussing.
: ☆─────────────────────────────────────☆
: Question 1.
: A deck of cards with
| f****e
发帖数: 590 | 5 求question 5的解法
─☆
connecting
are
【在 h********2 的大作中提到】
: ☆─────────────────────────────────────☆
: Question 5.
: A n*m matrix is composed of n*m unit cubes. Draw a diagonal line connecting
: two opposite corners of matrix, develop a formula showing how many cubes are
: crossed(touch on corner does not count as cross) by the diagonal line are
: any n and m.
: A: n+m-gcf(n,m), with gcf the greatest common factor.
| i******d
发帖数: 54 | 6
get
恩，这个解法很标准，很多教科书都是这个方法。
【在 f****e 的大作中提到】
: Question 1
: 这里E[N]是指随机抽取N张牌后，手里所剩牌的的期望值(不必理会stop when you get
: card N,因为继续抽下去手里的牌数也不会变）
: 那么E[N-1]就是你随机抽出N-1张手里的牌数的期望值
: 只有当card N是最后一张的时候这两个才会有区别，所以解答里那个方程体现了两者的
: 关系
:
: ─☆
|
|
