2008 Academic Challenge

Transcription

1 2008 Academic Challenge COMPUTER SCIENCE TEST - REGIONAL - - This Test Consists of 30 Questions - - Computer Science Test Production Team Jim Feher, McKendree College Author/Team Leader Kian Pokorny, McKendree College Author Scott Elliott, John A. Logan College Reviewer Don Wayman, WYSE Coordinator of Test Production GENERAL DIRECTIONS Please read the following instructions carefully. This is a timed test; any instructions from the test supervisor should be followed promptly. The test supervisor will give instructions for filling in any necessary information on the answer sheet. Most Academic Challenge sites will ask you to indicate your answer to each question by marking an oval that corresponds to the correct answer for that question. Only one oval should be marked to answer each question. Multiple ovals will automatically be graded as an incorrect answer. Be sure ovals are marked as. Not as,,, etc. If you wish to change an answer, erase your first mark completely before marking your new choice. You are advised to use your time effectively and to work as rapidly as you can without losing accuracy. Do not waste your time on questions that seem too difficult for you. Go on to the other questions, and then come back to the difficult ones later if time remains. *** TIME: 40 MINUTES *** DO NOT OPEN TEST BOOKLET UNTIL YOU ARE TOLD TO DO SO! 2008 Worldwide Youth in Science and Engineering WYSE, Worldwide Youth in Science and Engineering and the WYSE Design are service marks of and this work is Copyright 2008 by the Board of Trustees of the University of Illinois at Urbana - Champaign. All rights reserved.

2 WYSE Academic Challenge Computer Science Test (Regional) A computer system uses an 8 bit wide bus with a speed of 1MHz to transmit data. Which of the following is a best estimate of the amount of data that can be sent over this bus? Assume that one transmission can be made during every clock cycle. a) 8 bits per second b) 1,000,000 bits per second c) 1,000,000 bytes per second d) 8,000,000 bytes per second 2. A disadvantage of main memory (ram) over secondary storage (hard drives) is: a) that it is generally cheaper than secondary storage. b) that it does not save its state (values) when powered down. c) that it contains no moving parts. d) both share the properties listed above.. 3. Broadband (DSL and cable) service providers often provide an asymmetric connection for their clients. This can best be characterized as: a) a reliable connection that corrects for lost data. b) a connection allowing the maximum amount of data that can be sent from the client to be greater than amount sent to the client. c) a connection allowing the maximum amount of data that can be sent to the client to be greater than amount sent from the client. d) a connection providing more than one type of service for the connection (phone, internet and/or video).. 4. Which of the following is NOT a programming language that can be used to create dynamically changing websites? a) Perl b) HTML c) PHP d) JavaScript e) ASP (Active Server Pages) 5. The following Boolean relation provides an example of which property or law? a) Associative Property b) Distributive Property c) Additive Identity d) DeMorgan's Law e) None of the above not(a and B) = not A or not B

3 Computer Science 2 6. Determine the logical expression that corresponds to the OUTPUT of the following truth table. A B C OUTPUT F F F T F F T F F T F T F T T F T F F T T F T F T T F T T T T F a) C b) A and B c) (not A) or C d) not C 7. A particular CPU uses twelve bits to represent a binary number. How many different combinations can be represented? a) 2 12 b) 2 x 12 c) 12 2 d) 12! 8. Convert the base 16 number 75 from hexadecimal into binary. a) 117 b) 4B c) d) For the following logical circuit, the OUTPUT is equivalent to which expression below if A is true and B is false? a) True b) False c) C d) not C 10. If A is True and B is False, what is the value of the following Boolean expression? (C and A) or (A and not B) a) True b) False c) C d) not C

4 Computer Science 3 // Use the following code for the next two questions (11 & 12). int j=1, x = 2; for (j = 0; j<4; ++j) { cout << j*x+2; x = x+2; 11. What is printed by the code segment above? a) b) c) d) e) The variable j takes on which range of values as the code runs? a) b) c) d) This cannot be determined from the information given. e) None of the above. 13. What is printed by the following code segment? int a=0, b=2, c=4, d=6; if (!(a==b && c)!(c>d)) cout<<a+b+c+d; else if (!(!(d==c)&&(b!= a))) cout<< b-c+d; else cout<<c+d; a) 12 b) 10 c) 8 d) 6 e) 4 // The following code is used for the next two questions (14 & 15). void FUNC(int n) { int i=0; int f1 =1, f2=0, f = 0; for (i=2; i<=n;++i) { f = f1+f2; f2=f1; f1=f; cout<<f<<" "; 14. What is printed given the function call FUNC(5)? a) b) c) d) e) What argument would need to be sent to the function to print 1 2 3? a) 1 b) 2 c) 3 d) 4 e) 5

5 Computer Science Recursive functions are functions that a) return data repeatedly. b) are called many times in a given program. c) call other functions repeatedly. d) call themselves. // The following code is used for the next two questions (17 & 18). void FUNC( int n) { int i=0; int f1 =8, f2=8, f = 0; for(i=1; i<=n;++i) { f = 777%(f1-f2+i)+777%(i); ++f1; --f2; cout<<f<<" "; 17. What is printed given the function call FUNC(4)? a) b) c) d) For any nonnegative integer n and the function call FUNC(n), how many times is the loop entered? a) 1 b) 4 c) n d) n+1 e) n What is printed by the following code? int i; for (i=0; i<6; i=i+1) { switch (i/2) { case 0: cout << i; break; case 1: cout << i/2; default cout << 7; a) b) c) d) e) Given the following stack operations, what is the result of the stack? PUSH A, PUSH B, POP, POP, PUSH C, PUSH D, POP NOTE: The top of the stack is on the left. a) C b) ABCD c) DCBA d) D e) empty

6 Computer Science 5 // The following code is used for the next three questions (21, 22 & 23). const int SIZE = 3; int A[SIZE][SIZE] = { {1, 2, 3, {4, 5, 6, {7, 8, 9 ; int i, j, s=0; for(i=0; i<size; i++) { j = 0; do { s = s + A[i][j]; j++; while (j<i); cout << s; 21. What is the value that is displayed for the variable s when the entire block finishes? a) 10 b) 19 c) 20 d) The code block for the inner do/while loop will be reached several times, depending upon how many times the outer for loop is executed. What is the minimum number of times that the inner do/while loop will cycle through its code for any of the times that the do/while code block is reached? a) 0 b) 1 c) 2 d) What is the approximate running time for the code if the multi-dimensional array is of SIZE equal to n? a) O(n 1/2 ) b) O(log 2 (n)) c) O(n) d) O(n!) e) O(n 2 ) 24. Object Oriented Programming is a programming paradigm that a) is objectionable. b) considers data structures first and algorithms second. c) considers algorithms first and data structures second. d) All of the above. e) None of the above. 25. Which of the following instructions can not be used to repeatedly execute code segments? a) for b) while c) if d) do/while e) All can be used to repeatedly execute code.

7 Computer Science What is the order of the nodes visited from a postorder traversal of the tree below? A B C D E a) ABCDE b) DBECA c) ABDCE d) DBAEC 27. With a queue data structure, insertions and deletions occur at a) the front. b) the top. c) the rear. d) the bottom Given the following queue operations, what is the result of the queue? INSERT A, REMOVE, INSERT B, REMOVE, INSERT C, INSERT D, REMOVE, INSERT E, REMOVE NOTE: The front of the queue is on the right. a) empty b) C c) ABCD d) DCBA e) E 29. A constructor is used to a) create new functions needed to use private variables. b) help build a function when writing a program. c) initialize variables of a newly instantiated object. d) All of the above. e) None of the above. 30. Object Oriented Programming uses which of the following? a) data abstraction b) encapsulation c) inheritance d) polymorphism e) all of the above