CS131 Introduction to Computer Science I
Final Exam (200 Points)
Fall 2002, Section 1
Instructor: Jill Forrester
Name: _____________________________________________
Score: _____ /200
True/False (2 points each – 20 points total):
von Neumann originated the idea that instructions could be stored along
___________ John
with data in main memory.
___________ Computer Science is best described as the study of computers.
are four built-in data types in JavaScript: number, character, boolean, and
___________ There
string.
___________ JavaScript functions produce one or more outputs.
Turing created a computer called COLOSSUS during World War II to decrypt
___________ Alan
German secret messages.
___________ An assignment statement stores data to a variable in JavaScript.
___________ An integrated circuit is composed of thousands of vacuum tubes.
___________ Since writing one is difficult, an operating system is an example of hardware.
The delay experienced in transferring a piece of data from memory to the CPU in
___________ the Knob & Switch Computer was unrealistic since memory speed continues to
outpace processor speed.
___________ The Internet was developed to reduce paper consumption by the EPA.
Multiple Choice. Circle the best answer. (2 points each – 20 points total)
1. What has been called “the most important invention of the 20th century?”
a. The ENIAC Computer
b. Pokemon
c. High-level pogramming lnguages
d. The transistor
2. What is
a.
b.
c.
d.
meant by the term semiconductor?
A material that conducts electricity without a problem.
A material that does not conduct electricity.
A material that can have it's conductivity altered by the introduction of impurities.
A material that conducts electricity extremely well, but only at very low
temperatures.
3. An algorithm is
a. a component of cache memory.
b. a new type of system bus from Intel.
c. a logical sequence of steps to solve a problem.
d. part of the BIOS.
4. Which of the following is not a property of good design?
a. The resulting program is easier to debug.
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b. The resulting program will never have to be altered again.
c. The resulting program is easier to write.
d. The resulting program in easier to understand.
5. In which type of memory is access time independent of location?
a. Sequential Access Memory.
b. Random Access Memory.
c. Read-Only Memory.
d. Binary Memory.
e. None of the above
6. Pseudocode is
a. a new programming language from Microsoft.
b. an English-like description of an algorithm.
c. stepwise Refinement.
d. poorly written JavaScript code.
7. The clock speed of a CPU is determined by
a. how fast items can be transferred between the components of the CPU.
b. Eastern Standard Time.
c. the word size of the CPU.
d. the International Standards Organization.
8. Which
a.
b.
c.
d.
of the following is not a component of the von Neumann architecture:
Input and output devices
Memory
A Compiler
The Central Processing Unit
9. Which
a.
b.
c.
d.
of the following is a component of a Central Processing Unit?
A disk drive
Main memory
The data vortex
An arithmetic-logic unit
10. Which of the following expressions is equivalent to
if (g > 100) {
document.write(“Out of range”);
}
if (g < 0) {
document.write(“Out of range”);
}
a. if (g > 100 && g < 0) {
document.write(“Out of range”);
}
b. if (g > 100 && < 0) {
document.write(“Out of range”);
}
c. if (g > 100 || g < 0) {
document.write(“Out of range”);
}
d. none of the above.
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Short Answer (38 points total)
1. (10 points) For the following questions assume you are restricted to a fixed precision of
4 bits (i.e., numbers must consist of exactly 4 bits, no more, no less)
a. Convert the following to decimal:
i.
0110
ii.
1101
b. Perform the following addition in binary (show steps and final result in binary):
i.
1110 + 0010
ii.
Did the addition cause an overflow? Explain why or why not?
2. (10 points)
a. Explain the difference between a low-level language and a high-level language.
b. Would you categorize the following languages as low-level or high-level?
i.
machine code
ii.
JavaScript
iii.
assembly code
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3. (8 points) Of the eight statements listed below, six are stages of the Program
Development Life Cycle. Number the correct steps in the order they should occur.
_________ Code the program. Translate the algorithm into JavaScript syntax.
_________
Complete the documentation. Organize all material that describes the
program for future maintenance.
_________
Analyze and define the problem; i.e. understand what the program should
do; do a preliminary design of the GUI.
_________ Test the program and fix existing bugs.
_________ Ignore the problem. Perhaps it will go away.
_________ Design and Plan the solution to the problem. Formulate an algorithm.
_________
Based on the design of the solution, finalize the GUI. Determine how the
input will be obtained and how the output will be displayed.
_________
Upload the finished program onto alpha and put a link to it from your
homepage.
4. (10 points) Finish the truth table for the following circuit:
A
B
C
| Z
-----------------------0
0
0
|
0
0
1
|
0
1
0
|
0
1
1
|
1
0
0
|
1
0
1
|
1
1
0
|
1
1
1
|
Tracing JavaScript Code (38 points total)
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1. (12 points) What is returned by the following JavaScript function
function snafu(n) {
if (n == 0) {
return 0;
}
else if (n == 1) {
return 1;
} else if (n > 0) {
return 18 - Math.pow(n, 2) / 2 - 10;
}
return -1;
}
a. if we call snafu passing in 0?
b. if we call snafu passing in 4?
c.
if we call snafu passing in -10?
2. (14 points) Write the output of the following segment of code in the space below:
var numRows, currentCols, i, j;
numRows = 5;
currentCols = 5;
for(i = 1; i <= numRows; i = i + 1) {
for(j = 1; j <= currentCols; j = j + 1) {
document.write(j + " ");
}
document.write("<BR>");
currentCols = currentCols - 1;
}
3. (12 points) Consider the following JavaScript function definitions:
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function doSomething(str) {
var copy;
copy = "";
for (i = 0; i < str.length; i = i + 1) {
copy = str.charAt(i) + copy;
}
return copy;
}
function whatDoIDo(str) {
if(str.length % 2 == 0)
return doSomething(str);
else
return str.toUpperCase();
}
What is returned from the following function calls:
a. doSomething(“cow”)
b. whatDoIDo(“cat”)
c.
whatDoIDo(“deer”)
Writing JavaScript Code (84 points total)
1. (22 points) Suppose we are writing a program for an amusement park that sells tickets as
follows:
 $12.95 for children 12 or under
 $14.95 for seniors 65 or older
 $19.95 for all other park guests
The park wishes to keep track of how many tickets of each type are sold during the day.
Write a function called takeTickets that repeatedly prompts the ticket taker for an age
until a –1 is entered. For each age entered, the appropriate text box counter should be
updated (i.e., either add one to the senior, child, or adult count) and the appropriate price
should be displayed in another text box. The HTML for the page would appear in the body
as follows:
<FORM NAME=”TicketForm”>
<INPUT
<INPUT
<INPUT
<INPUT
TYPE=”text”
TYPE=”text”
TYPE=”text”
TYPE=”text”
NAME=”price” SIZE=8 VALUE=””> <BR>
NAME=”seniors” SIZE=6 VALUE=”0”> <BR>
NAME=”children” SIZE=6 VALUE=”0”> <BR>
NAME=”adults” SIZE=6 VALUE=”0”>
<!— Note: we also have a button that invokes takeTickets -->
</FORM>
Complete the function started for you below:
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function takeTickets() {
}
2. (22 points) The game of Yahtzee! involves rolling five six-sided dice. Players score points
based upon patterns produced by the dice (for example, three of the same number, etc.).
a. In order to play, we will have to simulate rolling five six-sided dice. Write code
below that will first generate a random integer from 1 to 6 and then select a die
image to display. Assume the images have names “die1.gif”, “die2.gif”, up to
“die6.gif” and that the image tag in the body is given as
<IMG NAME=”firstDie” SRC=”blank.gif”>
Note : you only have to write code for rolling a single die.
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b. A player scores a yahtzee if all five dice have the same number (e.g., five sixes
appear on the dice). Complete the if condition in the following function (use as
short a condition as possible):
function isYahtzee(die1, die2, die3, die4, die5) {
// Note that all parameters have numeric values
if(
)
return true; // we have a yahtzee
else
return false;
}
c.
A player scores a large straight if the value of the second die is one greater than
the value of the first die, the value of the third die is one greater than the value of
the second die, etc. for all of the dice. For example, 2 3 4 5 6 is a large straight
but 1 3 4 5 6 is not since 3 is not one greater than 1. For the following function,
you may assume that the values of the parameters are ORDERED; that is,
die1 <= die2 <= die3 <= die4 <= die5
Complete the if condition in the following function:
function isLargeStraight(die1, die2, die3, die4, die5) {
// Note that all parameters have numeric values
if(
)
return true; // we have a large straight
else
return false;
}
d. For this problem, you may assume that the following functions are already defined
for you:
 isThreeOfAKind(die1, die2, die3, die4, die5) – returns true if
exactly three of the dice passed into the function have the same value;
otherwise, returns false.
 isTwoOfAKind(die1, die2, die3, die4, die5) – returns true if
exactly two of the dice passed into the function have the same value;
otherwise, returns false.
In yahtzee, a full house occurs when exactly two of the dice have one value
while the three other dice have another value. For example, 3 3 3 2 2 and
1 1 4 4 4 are both full houses. In the following code, complete the
loop condition so that the loop continues until a full house is obtained or 100
rolls are completed. Complete the if condition to determine if a full house is
obtained.
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Remember…Complete both the loop condition and the if condition in the
following code:
var die1, die2, die3, die4, die5;
var fullHouse, numRolls;
fullHouse = false; // switch to true if we get a full house
numRolls = 0;
while (
)
{
// Assume the dice are rolled correctly here and that
// the local variables die1, die2, die3, die4, and die5
// contain the numeric values associated with the dice.
if (
) {
fullHouse = true; // we have a full house
}
numRolls = numRolls + 1;
}
3. (22 points) Write the following segments of code.
a. Create a JavaScript function called findSubstringStartingAt that takes two
input parameters (both strings, call them target and searchString). The
function finds the location of the first occurrence of searchString in the string
target and returns the rest of target starting at that position. For example,
findSubstringStartingAt("yabba dabba do", "d") returns "dabba
do". ( Hint: the return string can be built using two existing string methods.)
You should return the null (empty) string in the case where the searchString is
not found in the target.
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b. Create a JavaScript function called obscureChar that takes two input
parameters (both strings, call them target and searchChar) and returns the
target string with each instance of the searchChar replaced by an
asterisk (*). For example, obscureChar("yabba dabba do", "a") returns
"y*bb* d*bb* do". You may assume that the second string is a single character.
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4. (18 points)
a. Write a function called minimum that takes a single parameter indicating the
length of a sequence of numbers to be input by the user (that is, if 10 is passed
in, your function should prompt for a number 10 times). As your function
prompts for numbers, it should keep track of the smallest value entered by the
user. After all data is input, the function should return this minimum.
b. Suppose we wish to create an event-driven form that allows the user to specify a
sequence length in a text box and then call minimum by clicking a button. The
minimum value returned should be stored in a second text box.
<FORM NAME=”MinForm”>
<INPUT TYPE=”text” NAME=”length” SIZE=4 VALUE=””><BR>
<INPUT TYPE=”text” NAME=”min” SIZE=6 VALUE=””><BR>
<INPUT TYPE=”button” NAME=”findMin” VALUE=”Find Minimum”
????? >
</FORM>
Given the previous description of the desired behavior, indicate below what the
????? should be replaced with in the HTML above to make the web page work as
desired.
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Bonus Points
1. (2 points) What is your opinion of this test?
2. (1 point) Would you recommend this class to a friend?
3.
(1 point) What was your favorite lab or other assignment?
4. (1 point) What was your least favorite lab or other assignment?
Hope you learned something and enjoyed the course.
Have a wonderful winter break!
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