COMPUTERS CPSC230 & PROGRAMMING I FINAL Exercise SUMMER 2001 Department Of Physics, Computer Science and Engineering Christopher Newport University Student Name: ______________________________ Student ID: ______________________________
Part 1 Basic
1. 2. 3. 4. 5. 6. 7. 8. 9. Why is it necessary to include iostream in a program that uses cin and cout? What is a compiler? What's the name of the compiler we use for our course? What is the difference between an object and a class? What is the difference between class and struct? What is the difference between pass by value and pass by reference? List one advantage and one disadvantage of passing parameters by reference instead of by value. In the function foo (int t[], int size); is the array t passed by value or by reference? When would you use a do/while loop instead of a while loop? Members of a class specified as ____________ are accessible only by members of that class and by friends of that class.
10. What is the difference between a void and a non-void function? 11. Suppose your executable is named a.out. Write the complete UNIX command to execute a.out but redirect its input so that cin reads from the file input.dat. 12. Suppose x and y are two int variables different than zero. Write a statement that computes the real number that results from dividing x by y. Assume x and y are already declared. 13. Write a single C++ statement that will compute the value of the formula y = ax2+bx+c. 14. Write a statement that assigns random integers to the variable n in the following ranges: a) 0 n 11 b) -4 n 15 15. Declare a string variable called firstname and give it the value "John".
Part 2 Control Structures
16. Rewrite the following if/else statement using the conditional operator (?:)
if (x % 3 == 0) cout << "x is a multiple of 3"; else cout << "x is NOT a multiple of 3"; 17. A company gives its customers a 20% discount if they order 1000 or more of the same item; 15% if they order 500-999; 10% if they order 100-499; and no discount if quantity < 100. Write an if/else if/else statement that will figure out the amount of discount and the order total. Assume that the variables quantity, discount, subtotal (order subtotal before discount is applied), and total (order total after proper discount has been applied) have already been declared. 18. Write a nested if/else statement that would assign grades to students based on their overall average. The grade cutoffs are A:90, B:80, C:70, and D:60. Assume that the variables grade and avrg were defined as: char grade; double avrg; 19. Rewrite the following for loop using a while loop. for (TempF = 0; TempF <= 100; TempF += 10) { TempC = (TempF - 32.0) * 5.0 / 9.0; cout << TempF << " " << TempC << endl; } 20. Re-write the following code using a for loop instead of the while loop. x = 1; product = 1; while (x <= 8) { product *= x; x += 2; } 21. Write the code (using two nested for loops) that would print the following shape (notice there is a difference of 2 stars between two consecutive lines) ********** ******** ****** **** ** 22. Write the code (using two nested for loops) that would print the following shape ****** * * * * * * ****** 23. Using while loop to write the code (not an entire program) that will ask a user for a number. As long as the number given by the user is a multiple of 5, print that number out and ask the user for a new number.
Part 3 Functions
24. In the function foo (const int &x); is it possible for the function to modify the value of x? Why or why not? 25. Comment on the design of the following function: readAndPrintData (int dataArray[], int &arraySize). 26. A variable that can be accessed only within the function in which it was defined is called a _________ variable. A variable that can be accessed within any function is called a _________ variable. 27. In C++ it is possible to have various functions with the same name but different signatures. This is called function _____________________. 28. Write a function named triple that accepts as an input parameter one integer and returns triple that integer. For example, triple(4) will return the value 12. 29. Write a function named get that reads three integers from the user and passes their values back to the caller via output parameters. Here is an example of a call to this function: int x, y, z; get(x,y,z); cout << x << y << z; 30. Write a function named printNbrs that prints all even integers from 2 to 100, each on a separate line, using only one cout statement. 31. Write a function named rectangle which accepts as input parameters two integers h and w, and prints a rectangle consisting of * characters. w represents the number of * in a line (i.e. width), h represents the number of lines (i.e. height). 32. A shipping company charges $500 for the first 100 pounds and $1.50 for each extra pound of part thereof in excess of 100 pounds. Write a definition of the function calculateCharge to determine the shipping fee for a particular shipment. The argument to this function should be the weight in pounds of the shipment. 33. Define a function named isPositive() which accepts an integer parameter and returns true if that parameter is positive, otherwise it returns false. 34. Write the prototype and the definition of a function arrayMin that returns the minimum of the elements in a one-dimensional array of type double and size n. The arguments of this function should be the array itself and the size of the array. 35. The definition of the function convertFtoC that converts a Fahrenheit temperatures to Celsius are as follows: // function definition double convertFtoC (int fah) { return (fah - 32) * 5.0 / 9.0; } Use this function in a program to convert all Fahrenheit temperatures that are multiples of 5 in the range of 5-100 (i.e. 5, 10, 15, 20, 100) to Celsius temperatures and print the results in a nice tabular format. 36. Write a function that takes an array of integers and the integer size of the array as parameters and returns the difference between the sum of all the elements of the array located at even indices and the sum of all the elements of the array located at odd indices.
37. Given the definitions and the prototype below, write the definition of the function find that will find a particular value (val) in a bitmap (s). The function should return the value true if val is found and false if val is not found in the bitmap. If val is found, the parameters row and col indicate the row and column where val was found (only the first occurrence of val is reported). const int ROWS = 10; const int COLS = 40; struct bitmap { int map[ROWS][COLS]; int numRows; int numCols; }; bool find (const bitmap s, const int val, int &row, int &col);
Part 4 Arrays
38. State what happens in memory when the statement char x[10]; is executed. 39. Can an array contain elements of different types? 40. Define a 3 by 5 array of string. Call it nameTable. 41. Declare the array score of size 100 and type double, and initialize its first 5 elements to 1, 3, 5, 7, 9 and the remaining elements to 0. 42. Declare the array X of size 100 and type int. Using a for loop, initialize its elements to 3, 6, 9, 12, 300. 43. Declare the array Y of size 100 and type int. Using a for loop, initialize the elements of the array with even indices to 2 and the ones with odd indices to 3. 44. Consider the one-dimensional array t declared as int t[100]. Write single statements that perform the following operations: a) Initialize the elements of the array to zero b) Add 2 to every element the of array c) In one statement, declare the array score of type int and size 1000 and initialize its first three elements to 5, 10, 15 and the remaining elements to 0. 45. Consider a 4 by 10 integer array t. a) How many elements does t have? b) Write a nested for structure that initializes each element of t to 3. c) Write a statement that prints out the elements of the first row of t. d) Write a statement that prints out the elements of the second column of t.
Part 5 Structure and Class
46. A car is described by its make, model, and year. Define a struct named structCar to store such information about a car. 47. Answer parts a-c based on the following code: class Cjar { private:
const int increment; int count; string label; public: void set(string plabel); // set label to the value of plabel int get()const; // return the value of data member count }; a) The code below is the body of the implementation of member function get(). What is the error in it, and why is it an error? // body of function get() { count += increment; return count; }; b) Implement the constructor for Cjar. It should set increment to 1, count to zero, and label to "?????". c) Assume Cjar is correctly defined/implemented. The following code is from a client of the Cjar class. If there are errors, identify them. All required include files have been included. // code from client of Cjar const Cjar jar1; Cjar jar2; cout << jar1.get() << jar2.get(); jar2.set("Pickles"); 48. Fill in the blanks. #include <iostream> #include <string> class Customer { public: string FirstName; // customer first name string LastName; // customer last name int IdNumber; // customer unique ID int AcctNumber; // customer account number double AcctBalance; // customer account balance };
int main() { Customer john; cout << "Enter customer ID number" << endl; cin >> _____________________; cout << "Enter customer first and last name" << endl; cin >> _____________________ >> _____________________; return 0; } 49. Consider the struct Sstudent. It has two data members: name (a string), and GPA (a double). Suppose that we declared s to be an Sstudent. Write C++ code to print the name of s and the GPA of s.
50. Write a class declaration for a class called herd which represents a herd of dairy cows. This class should have a private variable to represent the size of the herd and two public member functions, one of which will set the size of the herd, and the other which will return it. You do not need to implement these functions. Choose appropriate variable types, function names, parameter types, return types, etc. 51. Write the declaration for a class called Box which can contain up to MAX_SIZE objects of type Toy. Assume that class Toy and the constant MAX_SIZE have been correctly defined. You should be able to put Toy objects into the Box, take objects out of the Box, search for a specific Toy, and find out how many Toys are currently stored in the Box. You do not need to implement any of the member functions.
Part 6 Tracing
52. What's wrong with the following code? double x; int y[10]; for (int i=0; i<10; i++) { cin >> x; y[i] = x; } 53. What's wrong with the following code? double x[10]; for (int i=0; i<=10; i++) cin >> x[i]; 54. What are the values of x and y after the following code is executed? int x = 17, y; x = x / 3; y = x % 3; 55. What are the values of x, y, and z after the following code is executed? int x = 19, y, z; x += 2; y = x++ % 3; z = --y; 56. Assume that x = 0, y conditions? a) (x < y) && (z b) (x <= y) || (y c) (w < z < y) d) (x < y) && ((y = 3, z = 5, and w = 8. What is the truth value (true/false) of the following != w) > z) + z) == w)
57. What is the value and data type of each of the following expressions? a) static_cast <int> (16.8) / 2 * 3; Type = _______ Value = _______ b) 20.0 - 36 / 9 * 4 % 4 + 1; Type = _______ Value = _______
58. What exactly will be printed by the following code? int x = x += 2; y = ++x z = y++ cout << 10, y, z; % 5; * 2; "x = " << x << " y = " << y << " z = " << z;
59. What is the value of x after each of the following statements is executed? a) x = floor ( fabs (-9 + ceil (-4.5))); //ceil(-4.5)= 4.0; fabs(-13.0) = 13.0; floor(13.0)=13.0 b) x = fabs ( 1 + ceil (3.2)); //ceil(3.2) =4.0; fabs(1+4.0) =5.0 c) x = floor (1.23456 * 1000 + 0.5) / 1000; //floor(1234.56+0.5)/1000 = floor(1235.06)/1000 = 1...