2. What are the two main components to the CPU and what do each of them do? 3. What is the difference between a compiler and an interpreter?

Transcription

1 COSC 117 Final Exam Spring 2011 Name: Part 1: Definitions & Short Answer (3 Points Each) 1. What do CPU and ALU stand for? 2. What are the two main components to the CPU and what do each of them do? 3. What is the difference between a compiler and an interpreter? 4. What are the basic types of instructions and the two basic types of control instructions? 5. In object oriented programming, what are the states and what are the methods?

2 6. What are precondition and postcondition loops? Give examples of each. 7. What is the difference between an Applet and an Application? 8. What happened when you overload an integer? 9. List the four integer data types in order of storage requirements, that is, least storage needed to most storage needed. 10. What are the restrictions to the data types that can be used in the test condition in a switch statement.

3 Part 2: Alice Program Traces (15 Points Each) 1. Discuss what the following Alice program does from the point of view of the user, be very explicit. State what the user sees and when. When the world starts the world.my first method event is run. When asked for input the user will type in the following numbers in the given order: 5, 4, 3, 4, 5, 4, 3, 4, 5. The world has an object variable named z. world Events When the world starts Do: world.my first method Methods world.my first method ( ) No variables While ( world.z <= 20 ) plato.a wz = world.z plato Methods plato.a ( [123] wz) t = 1 t set value to ( ask user for a number question = Enter a Number: ) If ( wz <= 20 ) socrates.a n = t wz = wz Else socrates.b socrates Methods socrates.a ( [123] n, [123] wz) d = 1 d set value to ( ( n + wz ) ) world.z set value to d socrates say ( d as a string ) socrates.b ( ) No variables socrates say Goodbye

4 2. Discuss what the following Alice program does from the point of view of the user, be very explicit. State what the user sees and when. When the world starts the world.my first method event is run. The snowman has an object variable called t which has an initial value of 0.. world Events When the world starts world.my first method Methods world.my first method ( ) No variables While ( snowman.t < 5 ) Do in order Do: snowman turn to face snowwoman snowwoman turn to face snowman snowwoman turn left ( ( snowman.t ) ) duration = 0.25 seconds snowman turn left 0.5 revolutions snowman move forward 5 meters snowwoman turn to face snowman snowman turn to face snowwoman snowman move forward 5 meters increment snowman.t by 1

5 Part 3: Java Program Traces (15 Points Each) 1. Determine the output of the following program for each of the given inputs. import java.util.scanner; public class FinalTrace1 { public static double B(double x) { while (x > 7) x -= 0.5; return x; public static double A(double x) { while (x < 5) x += 2; if (x >= 6) return B(x); return x; public static void main(string[] args) { Scanner keyboard = new Scanner(System.in); System.out.print("Input x: "); double x = keyboard.nextdouble(); System.out.print("Final x = " + A(x)); (a) 3 (b) 5 (c) 6.8 (d) 4.9 (e) 539

6 2. Determine the output of the following program for each of the given inputs. import java.util.scanner; public class FinalTrace2 { public static void Print(int [] Arr) { for (int i = 0; i < Arr.length; i++){ System.out.print(Arr[i] + " "); System.out.println(); public static void main(string[] args) { Scanner keyboard = new Scanner(System.in); System.out.print("Input list: "); int [] A = new int [1000]; int input = 1; int count = 0; while (input!= 0){ input = keyboard.nextint(); if (input!= 0){ A[count] = input; count++; int [] B = new int [count]; for (int i = 0; i < count; i++){ B[i] = A[i]; Print(B); for (int i = 0; i < count/2; i++){ int temp = B[i]; B[i] = B[B.length-i-1]; B[B.length-i-1] = temp; Print(B); for (int i = 0; i < count/2; i++){ B[i] = B[B.length-i-1]; B[B.length-i-1] = B[i]; Print(B); (a) (b)

7 3. Determine the output of the following program for each of the given inputs. import java.util.scanner; public class FinalTrace3 { public static String C(String x, int k) { return ""+x.charat(k); public static String B(String x, int j) { return x + C(x, j); public static String A(String x) { int j = 100; String y = ""; for (int i = 0; i < x.length(); i++, j--){ switch (x.charat(i)){ case ' ': y = B(y, i/2); break; case 'a': y = y + j; break; case 'i': y = y + i; break; default: y += x.charat(i); break; return y; public static void main(string[] args) { Scanner keyboard = new Scanner(System.in); String s = keyboard.nextline(); System.out.println(A(s)); (a) This is a test (b) Help (c) Good Night

8 4. Determine the output of the following program for each of the given inputs. import java.util.scanner; public class FinalTrace4 { public static void Print2DintArray(int A[][]) { for (int i = 0; i < A.length; i++){ for (int j = 0; j < A[0].length; j++){ System.out.printf("%6d", A[i][j]); System.out.println(); public static void main(string[] args) { Scanner keyboard = new Scanner(System.in); System.out.print("n = "); int n = keyboard.nextint(); int [][] A = new int [n][n]; for (int i = 0; i < n; i++){ A[i][0] = i+1; for (int i = 0; i < n; i++){ for (int j = 1; j < n; j++){ A[i][j] = A[i][0] * A[i][j-1]; Print2DintArray(A); (a) 3 (b) 4 (c) -1

9 Part 4: Java Coding (15 Points Each) 1. Write a program that will take an input of a positive integer number from the user, say n. Repeat the following process until n is equal to 1. If n is even replace n by n/2 and if n is odd replace n by 3n + 1. The program must print out the sequence along with a count of the number of numbers in the sequence. Also the calculation of the next number must be done in a function that takes in the last number and returns the next number.

10 2. Write a program that will take as input a positive integer n from the user, that is, the input could be 1 or 2 or 3 etc.. The program should calculate and output the sum of all the numbers from 1 to n and the product of all the numbers from 1 to n. That is, n and n. The program should continually ask the user for another number until the user inputs 0. Also, each calculation must be done in a function that takes in n and returns the sum or product. So you will have two functions, one to do the sum and one to do the product.

11 3. Write a program that will take an integer n from the user and create an array with n rows and n columns. The program should put the number 1/(i+j+1) in the (i, j) cell. So if the user typed in a 5 the array would look like the following. Use doubles for storing the array entries. 1 1/2 1/3 1/4 1/5 1/2 1/3 1/4 1/5 1/6 1/3 1/4 1/5 1/6 1/7 1/4 1/5 1/6 1/7 1/8 1/5 1/6 1/7 1/8 1/9

12 4. Write a program that takes in an entire line as a string and counts the number of uppercase letters. You may assume that there are no punctuation symbols in the string.

13 5. Write a program that will take two numbers from the user n and r. The program must then use a random number generator to toss a coin n times and determine the number of runs of r heads or more. It should then output this number to the screen. You do not need to store the sequence of coin tosses in an array but you may if it helps you write the code. For example, if the user inputs 20 3 then the program will randomly generate a sequence of 20 coin tosses and determine the number of runs of length 3 or more. So if the random tosses produced HHTHHHTTHTHHHHTHHTHH the program would return 2 since there are two runs of 3 or more heads, HHTHHHTTHTHHHHTHHTHH.

14 6. Write an applet that produces the following image. Get as close as you can with the pixel locations. Have a Good Summer is in green, the polygon is in red and all other shapes are in blue.