1.Jeff and Diamond like playing game of coins,One day they
designed a new set of rules:
1)Totally 10 coins
2)One can take away 1,2or 4 coins at one time by turns
3)Who takes the last loses.
Given these rules Whether the winning status is pre-determined or not
解答：
1：从后面开始考虑，最后肯定要留1个才能保证自己赢
2：所以要设法让对方留下2，3，5个
3：也就是要自己取后留下1，4，6，7，8，9。。。
4：如果自己取后留下6，对方取2个，与（3）矛盾，所以排除6
5：如果自己取后留下8，对方取4个，与（3）一样情况，所以也排除8
6：同样，9也不行，如果我抽后剩下9，对方抽2个，就反过来成对方抽剩成7个了，也与
（
3）矛盾，所以也排除
7：所以很显然，我只能抽剩1，4，7
8：因为只能抽后剩1，4，7才能赢，我先抽得话不可能达到这几个数，很显然，只能让
对
方先抽，也即是先抽的人输
2.the UI specialist Dafna found a problem that some of the
Items on the marketing document form overlapped with each other.
because this form was implemented by differnt developers and
they didn't care the particular appearance of one item.Product manager
Tidav decided to write one small checking tool to generate the overlapped
items on all forms.He called in his guys to discuss about it.
Suppose the input is the integer coordinates (x,y)od the items (all rectangl
es)
on one form.Construct an efficient methed to find out the overlapped items.
Hint:The most direct way to do so is comparing each items with
the others,Given 1000 forms.each with 100-1000items on average.
the O(n2) algorithm is costly.Some guru suggested that one O(n)
method could help only if 6.5 kilobytes extra storage is available.
One elite argued that he could cut down the number to 1%,It's now your
turn to describe the idea.write out the pseudocodes,vertify his
algorithm and propose more advanced optimization if possible.
3 in a file system ,data need not be sequentially located in physical
blocks,We use a number of tables storing nodes imformation.Suppose
now we use a fixed node size of variable-lenth n,it takes [n/(k-b)]
nodes to store this item.(Here b is a constant, signifying that
b words of each node contain control information,such as a link to the
next node).If the avarage length n of an Item is N,what choise
of k minimizes the average amount of storage space required?
(Assume that the average value of (n/(k-b)) mod 1 is equal to 1/2 ,for any
fixed k, as n varies)
