Carleton University Department of Systems and Computer Engineering SYSC Foundations of Imperative Programming - Winter 2012

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1 Carleton University Department of Systems and Computer Engineering SYSC Foundations of Imperative Programming - Winter 2012 Lab 6 - Prototyping a List Collection, Second Iteration Objective To continue the development of a C module that implements a list collection, which you started in Lab 5. Attendance/Demo To receive credit for this lab, you must make a reasonable effort to complete the four exercises, and demonstrate the code you complete. When you have finished all the exercises, call a TA, who will review the code you wrote. For those who don't finish early, a TA will ask you to demonstrate whatever code you've completed, starting about 30 minutes before the end of the lab period. Finish any exercises that you don't complete by the end of the lab on your own time. Instructions 1. Create a new Pelles C project called Lab6. The project type must be Win32 Console program (EXE). 2. Create a new source code file. This file should be saved as test_list.c and added to the project. 3. In test_list.c, define a main function that simply returns Create a new source code file. This file should be saved as intlist.c and added to the project. 5. Create a new source code file. This file should be saved as intlist.h. Next, from the menu bar select Project > Update all dependencies. In the project window, you should now see an Include files folder below the names of the two.c files. 6. Open the intlist.c file that you wrote for Lab 5 and copy/paste all the code from that file into the new intlist.c file in your Lab6 project. This file should now contain 4 functions: intlist_print, intlist_index, intlist_count and intlist_contains. 7. Open the intlist.h file that you wrote for Lab 6 and copy/paste all the code from that file into the new intlist.h file in your Lab6 project. This file should now contain function prototypes for 4 functions: intlist_print, intlist_index, intlist_count and intlist_contains. 8. Edit test_list.c so that it #include's intlist.h. 9. Build your project, and make sure that there are no compilation or linking errors. 10. You might want to review the discussion of arrays and lists in the Lab 5 handout. In particuticular, it is important to know the following terms when working with lists: list length: the number of items currently stored in a list 1

2 list size: a synonym for length list capacity: the maximum number of items that can be stored in a list In Exercises 1 through 3, you are going to define more functions that operate on lists of integers. For this lab, a list will again be implemented as a fixed-capacity array of integers. (We`ll change this in a subsequent lab.) These function definitions will be stored in intlist.c. The function prototypes will be stored in intlist.h. For those students who already know C or C++: when writing the functions, do not use structs. They aren't necessary for this lab. For each exercise, you will have to write a test function in test_list.c. These test functions will be called by your main function. The test functions will not be interactive; i.e.they should not prompt the user for input. The test functions do not have to verify that the functions in intlist.c are correct; but they must print enough information so that the user can determine which function is being tested and whether or not is is correct;. in other words, each test function should print: the name of the function in intlist.c that is being tested the values that are passed as arguments to that function the expected results when the function is executed the actual results when the function is executed The test functions should call intlist_print to print the lists Finish each exercise (i.e., write the function that performs the specified list operation and its test function) before you move on to the next one. Don't leave testing until after you've written all your functions. Complete any exercises that you don't finish in the lab period on your own time, as "homework". Make sure you save a copy of your project. You'll need it for Lab 7. Exercise 1 In intlist.c, define a function that appends an integer to the end of list elems, which contains len integers. (Notice that parameter len is the length (size) of the list). The function prototype is: int intlist_append(int elems[], int len, int capacity); Parameter capacity is the list's capacity. If the function is successful, it should return the length (size) of the modified list. 2

3 If the function was not successful because the list was full when the function was called, it should return -1 and leave the list unchanged. This return value indicates to the caller that it is an error to attempt to append a value to a full list. message if len is negative. Remember to declare the function's prototype in intlist.h. In test_list.c, define a function named test_intlist_append that tests intlist_append. See the section, Test Functions, for general requirements for all test functions. Your test function should provide the following test cases, which should use a list with capacity 5: append 6 to an empty list (intlist_append should return 1); append 3 to this list: [6] (intlist_append should return 2); append 4 to this list: [6, 3] (intlist_append should return 3); append 7 to this list: [6, 3, 4] (intlist_append should return 4); append 2 to this list: [6, 3, 4, 7] (intlist_append should return 5); append 9 to this list: [6, 3, 4, 7, 2] (intlist_append should return -1); Build and run the project. Examine the test output to determine if intlist_append passes its Exercise 2 In intlist.c, define a function that deletes the integer at the specified position in list elems, which contains len integers. (Notice that parameter len is the length (size) of the list). The function prototype is: int intlist_delete(int elems[], int len, int i); Parameter i is the index (position) of the item that should be removed. If a list contains len items, the valid indices range from 0 to len - 1. If the function is successful, it should return the length (size) of the modified list. If the function was not successful because the list is empty (parameter n is 0), it should return -1. If the function was not successful because parameter i is not a valid index, the function should return -1 and leave the list unchanged.. message if len is negative. 3

4 Remember to declare the function's prototype in intlist.h. When your function deletes the integers at position i, the array elements at positions 0 through i-1 will not change; however, the elements at positions i+1 through len-1 must all be "shifted" one position to the left. Example: if a list contains [2, 4, 6, 8, 10], then calling intlist_delete with i equal to 2 changes the list to [2, 4, 8, 10]. Notice that 8 has been copied from position 3 to position 2, and 10 has been copied from position 4 to position 3. In test_list.c, define a function named test_intlist_delete that tests intlist_delete. Your test function should provide the following test cases: delete the integer at index 0 in a list containing 0 integers (intlist_delete should return -1); delete the integer at index 0 in this list: [5] (intlist_delete should return 0); delete the integer at index 0 in this list: [5, 3, 2 ] (intlist_delete should return 2); delete the integer at index 1 in this list: [5, 3, 2 ] (intlist_delete should return 2); delete the integer at index 2 in this list: [5, 3, 2 ] (intlist_delete should return 2); delete the integer at index -1 in this list: [5, 3, 2 ] (intlist_delete should return -1); delete the integer at index 3 in this list: [5, 3, 2 ] (intlist_delete should return -1). Build and run the project. Examine the test output to determine if intlist_delete passes its Exercise 3 In intlist.c, define a function that removes the first occurrence of an item equal to target in list elems, which contains len integers. The function prototype is: int intlist_remove(int elems[], int len, int target); If target is found and removed from the list, the function should return the length (size) of the modified list. If target is not found (either because it is not in the list or the list is empty), the function should return -1. This return value indicates to the caller that it is an error to attempt to remove a value that is not in the list. message if n is negative. Remember to declare the function's prototype in intlist.h. Notice that, if target is found at index i, the elements at positions 0 through i-1 will not change; however, the elements at positions i+1 through len-1 must all be "shifted" one position 4

5 to the left. Example: if a list contains [2, 4, 6, 8, 10], then calling intlist_remove with target equal to 8 changes the list to [2, 4, 6, 10]. Hint: you can implement this function in only few lines of code by using one or more of the other functions in your module. In test_list.c, define a function named test_intlist_remove that tests intlist_remove. Your test function should provide the following test cases: remove 5 from a list containing 0 integers (intlist_remove should return -1); remove 5 from this list: [5] (intlist_remove should return 0); remove 5 from this list: [7] (intlist_remove should return -1); remove 5 from this list: [5, 3, 2] (intlist_remove should return 2); remove 5 from this list: [3, 2, 5] (intlist_remove should return 2); remove 5 from this list: [7, 5, 2] (intlist_remove should return 2); remove 5 from this list: [3 8, 6] (intlist_remove should return -1); remove the first 5 from this list: [7, 5, 3, 6, 5, 2] (intlist_remove should return 5). Build and run the project. Examine the test output to determine if intlist_remove passes its Exercise 4 Modify the code in test_list.c so that all the arrays are dynamically allocated from the heap; in other words, instead of declaring fixed capacity arrays this way: int a[5]; use malloc to allocate arrays with the required capacity. (C's malloc function was discussed in class on Feb. 16.) You shouldn't need to change any of your list functions in intlist.c. Build and run the project, and verify that all of the list functions pass their Posted: Thursday, February 16,