May 23, 2005
Arrival
Protocol Handbook
Arrival
Stimuli needed:
1. Consent form
2. Pen
Preparation:
1. If subject is a novice, get consent form A… Else if subject is an expert, get consent form B… Else get consent form C.
2. Get pen for subject.
(Take subject to library in ICS 2. (ICS2 257))
(Have subject take a seat at a table. Have consent form and pen at hand.)
“Thank you for taking the time to participate in our human research project. We would like to remind you that participating in this research project is completely voluntary and you are welcome to leave at any time. However, to receive your compensation, you must complete to the best of your ability all requested questionnaires and task experiments. We estimate the experiment to last for about two and a half to three hours. Is this okay with you?”
(If subject agrees, continue…)
(Give consent form to subject)
“This is a consent form that contains information about our studies and how our research will be carried out. It also contains important information on confidentiality and the risks involved. Please read over this form carefully. After reviewing this form, please print your name at the top of page one clearly and sign and date on page three. If you have any questions, feel free to ask them at any time.”
“Print name clearly here.”
(Highlight and point to top of page where subject prints name)
“Sign and date here.”
(Highlight and point to page three where subject signs name)
(Give pen to subject)
“Please hand in your form and pen to me when you are finished.”
(When subject hands in consent form, double check printed name and signature. Review with subject over the spelling of subjects name to ensure legibility. Then print and sign your name on page three).
(File subject’s consent form in correct filing folder).
(If subject = A, Go to Task prompt… Else go to Questionnaire)
Posted by Derrick at 9:42 AM | Comments (0)
May 8, 2005
CS Questionairre
Given that the starting vertex is node 56 (root), the breadth first traversal of the above sorted-binary tree is:
56 18 65 16 45 63 78 7 17 23 53 57 64 73 86
Question 1.
Give the pseudocode for the breadth-first traversal.
Question 2.
What is the running time (big-O) of the breadth-first traversal?
Question 3.
Given the following sentence:
“The fast dog jumped over the fence”
Give the pseudocode that will give the following result:
“fence the over jumped dog fast The”
The original sentence is given to you in a character array. Meaning “T” is in array position 0, “h” is in array position 1, “e” is in array position 2, “ “(space) is in array position 2, etc etc.
Your result should be returned in a character array.
Your algorithm should be as efficient as possible.
Question 4.
What are the stages of the Waterfall model of software development?
Question 5.
Match the following programming languages to their respective type.
C++ Functional
Pascal Object Oriented
Perl Logic
Lisp Scripting
VHDL Procedural
Prolog Hardware Descriptive
General questions
How much web development experience do you have?
Was this experience for personal or professional reasons?
If any, what web development software have you used?
Posted by Derrick at 9:18 PM | Comments (0)
August 19, 2004
Collection of CS Questions
Collection of CS Questions Test: Similar to GRE questions. 1. Given a rectangular (cuboidal for the puritans) cake with a rectangularpiece removed (any size or orientation), how would you cut the remainder of the cake into two equal halves with one straight cut of a knife ?2. You're given an array containing both positive and negative integers and required to find the subarray with the largest sum (O(N) a la KBL). Write a routine in C for the above.
3. Given an array of size N in which every number is between 1 and N, determine if there are any duplicates in it. You are allowed to destroy the array if you like. [ I ended up giving about 4 or 5 different solutions for this, each supposedly better than the others ].
4. Write a routine to draw a circle (x ** 2 + y ** 2 = r ** 2) without making use of any floating point computations at all. [ This one had me stuck for quite some time and I first gave a solution that did have floating point computations ].
5. Given only putchar (no sprintf, itoa, etc.) write a routine putlong that prints out an unsigned long in decimal. [ I gave the obvious solution of taking % 10 and / 10, which gives us the decimal value in reverse order. This requires an array since we need to print it out in the correct order. The interviewer wasn't too pleased and asked me to give a solution which didn't need the array ].
6. Give a one-line C expression to test whether a number is a power of 2. [No loops allowed - it's a simple test.]
7. Given an array of characters which form a sentence of words, give an efficient algorithm to reverse the order of the words (not characters) in it.
8. How many points are there on the globe where by walking one mile south, one mile east and one mile north you reach the place where you started.
9. Give a very good method to count the number of ones in a 32 bit number. (caution: looping through testing each bit is not a solution).
10. What are the different ways to say, the value of x can be either a 0 or a 1. Apparently the if then else solution has a jump when written out in assembly. if (x == 0) y=0 else y =x There is a logical, arithmetic and a datastructure soln to the above problem.
11. Reverse a linked list.
12. Insert in a sorted list
13. In a X's and 0's game (i.e. TIC TAC TOE) if you write a program for this give a gast way to generate the moves by the computer. I mean this should be the fasteset way possible. The answer is that you need to store all possible configurations of the board and the move that is associated with that. Then it boils down to just accessing the right element and getting the corresponding move for it. Do some analysis and do some more optimization in storage since otherwise it becomes infeasible to get the required storage in a DOS machine.
14. I was given two lines of assembly code which found the absolute value of a number stored in two's complement form. I had to recognize what the code was doing. Pretty simple if you know some assembly and some fundaes on number representation.
15. Give a fast way to multiply a number by 7.
16. How would go about finding out where to find a book in a library. (You don't know how exactly the books are organized beforehand).
17. Linked list manipulation.
18. Tradeoff between time spent in testing a product and getting into the market first.
19. What to test for given that there isn't enough time to test everything you want to.
20. First some definitions for this problem: a) An ASCII character is one byte long and the most significant bit in the byte is always '0'. b) A Kanji character is two bytes long. The only characteristic of a Kanji character is that in its first byte the most significant bit is '1'. Now you are given an array of a characters (both ASCII and Kanji) and, an index into the array. The index points to the start of some character. Now you need to write a function to do a backspace (i.e. delete the character before the given index).
21. Delete an element from a doubly linked list.
22. Write a function to find the depth of a binary tree.
23. Given two strings S1 and S2. Delete from S2 all those characters which occur in S1 also and finally create a clean S2 with the relevant characters deleted.
24. Assuming that locks are the only reason due to which deadlocks can occur in a system. What would be a foolproof method of avoiding deadlocks in the system.
25. Reverse a linked list.
26. Write a small lexical analyzer - interviewer gave tokens. expressions like "a*b" etc.
27. Besides communication cost, what is the other source of inefficiency in RPC? (answer : context switches, excessive buffer copying). How can you optimise the communication? (ans : communicate through shared memory on same machine, bypassing the kernel _ A Univ. of Wash. thesis)
28. Write a routine that prints out a 2-D array in spiral order!
29. How is the readers-writers problem solved? - using semaphores/ada .. etc.
30. Ways of optimizing symbol table storage in compilers.
31. A walk-through through the symbol table functions, lookup() implementation etc - The interv. was on the Microsoft C team.
32. A version of the "There are three persons X Y Z, one of which always lies".. etc..
33. There are 3 ants at 3 corners of a triangle, they randomly start moving towards another corner.. what is the probability that they don't collide.
34. Write an efficient algo and C code to shuffle a pack of cards.. this one was a feedback process until we came up with one with no extra storage.
35. The if (x == 0) y = 0 etc..
36. Some more bitwise optimization at assembly level
37. Some general questions on Lex Yacc etc.
38. Given an array t[100] which contains numbers between 1..99. Return the duplicated value. Try both O(n) and O(n-square).
39. Given an array of characters. How would you reverse it. ? How would you reverse it without using indexing in the array.
40. GIven a sequence of characters. How will you convert the lower case characters to upper case characters. ( Try using bit vector - sol given in the C lib -> typec.h)
41. Fundas of RPC.
42. Given a linked list which is sorted. How will u insert in sorted way.
43. Given a linked list How will you reverse it.
44. Tell me the courses you liked and why did you like them.
45. Give an instance in your life in which u were faced with a problem and you tackled it successfully.
46. What is your ideal working environment. ( They usually to hear that u can work in group also.)
47. Why do u think u are smart.
48. Questions on the projects listed on the Resume.
49. Do you want to know any thing about the company.( Try to ask some relevant and interesting question).
50. How long do u want to stay in USA and why?
51. What are your geographical preference?
52. What are your expecctations from the job.
53. Give a good data structure for having n queues ( n not fixed) in a finite memory segment. You can have some data-structure separate for each queue. Try to use at least 90% of the memory space.
54. Do a breadth first traversal of a tree.
55. Write code for reversing a linked list.
56. Write, efficient code for extracting unique elements from a sorted list of array. e.g. (1, 1, 3, 3, 3, 5, 5, 5, 9, 9, 9, 9) -> (1, 3, 5, 9).
57. C++ ( what is virtual function ? what happens if an error occurs in constructor or destructor. Discussion on error handling, templates, unique features of C++. What is different in C++, ( compare with unix).
58. Given a list of numbers ( fixed list) Now given any other list, how can you efficiently find out if there is any element in the second list that is an element of the first list (fixed list).
59. GIven 3 lines of assembly code : find it is doing. IT was to find absolute value.
60. If you are on a boat and you throw out a suitcase, Will the level of water increase.
61. Print an integer using only putchar. Try doing it without using extra storage.
62. write C code for deleting an element from a linked listy traversing a linked list efficient way of elimiating duplicates from an array
63. what are various problems unique to distributed databases
64. declare a void pointer a) void *ptr;
65. make the pointer aligned to a 4 byte boundary in a efficient manner a) assign the pointer to a long number and the number with 11...1100 add 4 to the number
66. what is a far pointer (in DOS)
67. what is a balanced tree
68. given a linked list with the following property node2 is left child of node1, if node2 < node1 els, it is the right child.
O P
|
|
O A
|
|
O B
|
|
O C
How do you convert the above linked list to the form without disturbing the property. Write C code for that. O P
|
|
O B
/ \
/ \
/ \
O ? O ?
determine where do A and C go
69. Describe the file system layout in the UNIX OS a) describe boot block, super block, inodes and data layout
70. In UNIX, are the files allocated contiguous blocks of data a) no, they might be fragmented how is the fragmented data kept track of a) describe the direct blocks and indirect blocks in UNIX file system
71. Write an efficient C code for 'tr' program. 'tr' has two command line arguments. They both are strings of same length. tr reads an input file, replaces each character in the first string with the corresponding character in the second string. eg. 'tr abc xyz' replaces all 'a's by 'x's, 'b's by 'y's and so on. a) have an array of length 26. put 'x' in array element corr to 'a' put 'y' in array element corr to 'b' put 'z' in array element corr to 'c' put 'd' in array element corr to 'd' put 'e' in array element corr to 'e' and so on. the code
while (!eof)
{
c = getc();
putc(array[c - 'a']);
}
72. what is disk interleaving
73. why is disk interleaving adopted
74. given a new disk, how do you determine which interleaving is the best a) give 1000 read operations with each kind of interleaving determine the best interleaving from the statistics 75. draw the graph with performace on one axis and 'n' on another, where 'n' in the 'n' in n-way disk interleaving. (a tricky question, should be answered carefully)
76. I was a c++ code and was asked to find out the bug in that. The bug was that he declared an object locally in a function and tried to return the pointer to that object. Since the object is local to the function, it no more exists after returning from the function. The pointer, therefore, is invalid outside.
77. A real life problem - A square picture is cut into 16 sqaures and they are shuffled. Write a program to rearrange the 16 squares to get the original big square.
Posted by kim at 9:08 AM | Comments (0)
IQ Style Questions
IQ Style questions
Tests: Natural intelligence?
1. Which one of the five choices makes the best comparison? LIVED is to DEVIL as 6323 is to:
2336
6232
3236
3326
6332
2. Which one of these five is least like the other four?
Horse
Kangaroo
Cow
Deer
Donkey
3. Which number should come next? 144 121 100 81 64 ?
17
19
36
49
50
4. Even the most ___________ rose has thorns.
Ugly
Weathered
Elusive
Noxious
Tempting
5. HAND is to Glove as HEAD is to
Hair
Hat
Neck
Earring
Hairpin
7. John likes 400 but not 300; he likes 100 but not 99; he likes 3600 but not 3700. Which does he like?
900
1000
1100
1200
8. A fallacious argument is:
Disturbing
Valid
False
Necessary
9. If you rearrange the letters "ANLDEGN," you would have the name of a(n):
Ocean
Country
State
City
Animal
10. NASA received three messages in a strange language from a distant planet. The scientists studied the messages and found that "Necor Buldon Slock" means "Danger Rocket Explosion" and "Edwan Mynor Necor" means "Danger Spaceship Fire" and "Buldon Gimilzor Gondor" means "Bad Gas Explosion". What does "Slock" mean?
Danger
Explosion
Nothing
Rocket
Gas
11. If some Wicks are Slicks, and some Slicks are Snicks, then some Wicks are definitely Snicks. The statement is:
True
False
Neither
12. Ann is taller than Jill, and Kelly is shorter than Ann. Which of the following statements would be most accurate?
Kelly is taller than Jill
Kelly is shorter than Jill
Kelly is as tall as Jill
It's impossible to tell
13. A boy is 4 years old and his sister is three times as old as he is. When the boy is 12 years old, how old will his sister be?
16
20
24
28
32
14. Assume that these two statements are true: All brown-haired men have bad tempers. Larry is a brown-haired man. The statement Larry has a bad temper is:
True
False
Unable to determine
15. Two girls caught 25 frogs. Lisa caught four times as many as Jen did. How many frogs did Jen catch?
4
5
8
10
15
16. Inept is the opposite of:
Healthy
Deep
Skillful
Sad
Happy
17. A car traveled 28 miles in 30 minutes. How many miles per hour was it traveling?
28
36
56
58
62
18. If all Zips are Zoodles, and all Zoodles are Zonkers, then all Zips are definitely Zonkers.
The above sentence is logically:
True
False
Neither
19. Sue is both the 50th best and the 50th worst student at her school. How many students attend her school?
50
75
99
100
101
20. In a race from point X to point Y and back, Jack averages 30 miles per hour to point Y and 10 miles per hour back to point X. Sandy averages 20 miles per hour in both directions. Between Jack and Sandy, who finished first?
Jack
Sandy
They tie
Neither
Impossible to tell
Posted by kim at 8:59 AM | Comments (0)