2005年10月底，Google在美国《麻省技术评论》、《LinuxJournal》、《Mensa》、《今日物理》等几本专业杂志上，刊登了一份“Google实验室能力倾向测试”。试卷开头，蛊惑地写着“试试看！把答案寄回 Google，你有希望去Google总部参观，并成为我们其中一员”。
1. Solve this cryptic equation, realizing of course that values for M and E could be interchanged. No leading zeros are allowed.
WWWDOT – GOOGLE = DOTCOM
2. Write a haiku describing possible methods for predicting search traffic seasonality.
3.
1 1 1 2 1 1 2 1 1 1 1 1 2 2 1
What is the next line?
4. You are in a maze of twisty little passages, all alike. There is a dusty laptop here with a weak wireless connection. There are dull, lifeless gnomes strolling about. What dost thou do?
5. What’s broken with Unix? How would you fix it?
6. On your first day at Google, you discover that your cubicle mate wrote the textbook you used as a primary resource in your first year of graduate school. Do you:
7. Which of the following expresses Google□ over-arching philosophy?
8. How many different ways can you color an icosahedron with one of three colors on each face?
What colors would you choose?
9. This space left intentionally blank. Please fill it with something that improves upon emptiness.
10.On an infinite, two-dimensional, rectangular lattice of 1-ohm resistors, what is the resistance between two nodes that are a knight’s move away?
11.It’s 2 PM on a sunny Sunday afternoon in the Bay Area. You’re minutes from the Pacific Ocean, redwood forest hiking trails and world class cultural attractions. What do you do?
12.In your opinion, what is the most beautiful math equation ever derived?
13. Which of the following is NOT an actual interest group formed by Google employees?
14.What will be the next great improvement in search technology?
15.What is the optimal size of a project team, above which additional members do not contribute productivity equivalent to the percentage increase in the staff size?
16.Given a triangle ABC, how would you use only a compass and straight edge to find a point P such that triangles ABP, ACP and BCP have equal perimeters? (Assume that ABC is constructed so that a solution does exist.)
17.Consider a function which, for a given whole number n, returns the number of ones required when writing out all numbers between 0 and n. For example, f(13)=6. Notice that f(1)=1. What is the next largest n such that f(n)=n?
18.What’s the coolest hack you’ve ever written?
19.’Tis known in refined company, that choosing K things out of N can be done in ways as many as choosing N minus K from N: I pick K, you the remaining.
Find though a cooler bijection, where you show a knack uncanny, of making your choices contain all K of mine. Oh, for pedantry: let K be no more than half N.
20.What number comes next in the sequence: 10, 9, 60, 90, 70, 66,?
21.In 29 words or fewer, describe what you would strive to accomplish if you worked at Google Labs.
结果：答案是 777589 - 188103 = 589486 (3,6可以互换)
参考：http://www.cnblogs.com/calmzeal/archive/2005/11/24/283734.html
Answer：
十万万千百十个
W W W D O T
- G O O G L E
------------------
D O T C O M
hint：
1。 共出现10个不同字母，只有M和E能互换，所以0到9 都要出现
2。 十位数那一列，应为O - L = O (十位，个位均无借位 ==>L = 0)
或者10+O-L=O(十位有借位==>L =10)
或者O - L = O + 1(个位有借位 ==> L = -1)
或者10+O-L=O+1(十位个位均有借位 ==> L =9)
===>L = 0 (十位，个位均无借位)
或 L = 9 (十位个位均有借位)
3。 万和千那一列
W - O = O ,W - O = T 而O <> T,说明肯定有进位
万位无借位时：
3.1。 if W = O + O(万位) then W = O + T + 1(千位) ===>
W = G + D,W = O + O,O = T + 1,10 + D =G + C, L =0
(或10 + D =G + C + 1 , L = 9)
===>对W 用偶数枚举 ===> 无解
3.2。 if W = O + O + 1(万位) then W = O + T(千位) ===>
W = G + D, W= O + O + 1, 10 + W = O + T (或10 + W = O + T + 1)
===> T =11 or T =10 ===> 无解
万位有借位时：
3.2。 if 10 + W =O + O(万位) then w = O + T(千位) ==>
O = 10 + T ===>无解
3.3。 if 10 + W = O + O + 1(万位), then 10 + W = O + T(千位) ==>
W = G + D + 1,W + 10 = O + O + 1,T = O + 1,
(D=G+C,L=0)或(D=G+C+1,L=9)==>对W=1,3,5,7进行枚举
==>777589 - 188103 =589486(3,6可以互换)