CS 112a
Fall 2000
Ileana Streinu

General description

Part I
Basic C++ programming concepts and Basic data structures (50 points)

1. (6 points) What is the following (partial) program doing? (Explain in a few very short sentences, in English, on the right of the page next to the program code).
   
   int a[20];
   int n; int x;
   int choice;
   
   ....
   // the choice variable gets a value somewhere here
   //and the array a and the variables n and x are initialized
   ...
   
   int i;
   switch(choice)
   case 0:
   {
   v=0; val=a[0];
   for (i = 1 ; i < n ; i++)
   if (a[i]>val) {val=a[i]; v=i;}
   }
   cout << val << endl;
   
   case 1:
   {
   v=0;
   for (i = 0 ; i < n ; i++)
   if (a[i]==x) v=i;
   }
   cout << v << endl;
   
   case 2:
   {
   for (i = 0 ; i < n-1 ; i++)
   a[i]=a[i+1];
   }
   ....
   
   
   
   
   
   
   
   
2. (5 points) Write (in the space below) the definition and full code for a C++ function (NOT a main program) to compute the second largest element of an array of n elements. The function returns the second largest value (not index), and it has two parameters: the array and its number of elements.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
3. (3 points) Templates. Extend the previous C++ function to a template, capable of finding the second largest element of a general array whose elements are of a type that can be compared with the usual C++ comparison operator <.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
4. Classes. (2 points) Define a class named Pumpkin. Each Pumpkin has an id (integer), a color (recorded as an integer code) and a weight (integer). In the space below, start writing the class definition, as it would appear in the header file - only the class variables, no functions yet.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   Now finish the definition of the class, as well as make use of this class, by answering the following questions. Use the space below each question to write the answer.
   1. (2 points) The Pumpkin class description should be in a file named .........................
      
      
   2. (2 points) The implementation of the functions of the Pumpkin class should be in a file named .........................
      
      
   3. (3 points) Describe the structure of a Makefile for compiling and testing your class Pumpkin. The Makefile should obey the rules of structured object-oriented programming, which each class compiled separately.
      
      
      
      
      
      
      
      
   4. (3 points) Describe the structure of a Makefile for compiling and testing the class Pumpkin, assuming that you are only writing the testdriver and get the Pumpkin class from a library of pre-compiled code. More precisely, you should assume that I have written and compiled the Pumpkin class separately, and have made available to you the necessary files for using it, but not the class code.
      
      
      
      
      
      
      
      
   5. (2 points) Write the code for an empty Pumpkin constructor. By "empty", I mean that it is meant to be used in constructing an object of this type without giving it any specific values provided by the user - but rather initializing the variables with some defaults values (e.g. all 0's).
      
      
      
      
      
   6. (2 points) Write the code for a Pumpkin constructor that takes in three integers (corresponding to id, color and weight values) and initializes the current object with those values.
      
      
      
      
      
      
      
      
      
      
   7. (2 points) Write the code for a Print method, which prints on the standard output the values of the three variables of the current Pumpkin object.
      
      
      
      
      
      
      
      
      
      
   8. (2 points) Write a statement that declares a variable of type Pumpkin.
      
      
      
      
      
   9. (2 points) Write a statement that declares a variable of type Pumpkin with initial values (35, 2, 97).
      
      
      
      
      
   10. (2 points) Write a statement that applies the method Print on the object of type Pumpkin, which has been created at the previous step.
       
       
       
       
       
   11. (2 points) Write a C++ function to assign a color to the current Pumpkin object. Separately, write a statement showing how you would use this function on the variable defined at step 8 above.
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       
5. (3 points) Sorting Run the Insertion Sort algorithm on the following array of integers:
   
   { 5, 23, 21, 15, 13, 19}
   
   I mean: I do not want to see only the final sorted array!! You should work in stages, following the Insertion Sort algorithm. At each stage, write down how the array currently looks. You do not need to explain what the algorithm does. You do not need to write the code for the algorithm. Just show the array, after each stage.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
6. (3 points) Arithmetic expressions in postfix form. Write the prefix and postfix forms for the following arithmetic expression: (((2-3)/(7+1))/((3+2)-(2*3)))
   
   
   
   
   
   
   
   
   
   
   
   
7. (4 points) Evaluating arithmetic expressions in postfix form. Find he value of the following arithmetic expression written in postfix form (assumming that we only use one-digit decimal integers): 34+2*23+-2/ Apply the algorithm we discussed in class. Trace the execution of the algorithm, and show in sequence how the stack looks like at each step (i.e. after each push and pop). Redraw the stack, do not overwrite.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

Part II: hands-on programming (50 points)

To submit:
1. A file named mid.cpp containing your code.
2. A typescript showing what you have accomplished.
3. All submitted by 10:20 as submit Mid.