Lab 7 — List Implementation
Checkpoint 1
estimate: 20-30 minutes
The implementation of the dslist class in dslist.h is incomplete. In particular, the class is missing the destroy_list private member function that is used by the destructor and the clear member function. The provided test case in checkpoint1.cpp works “fine”, so what’s the problem?
Before we fix the problem, let’s use Dr. Memory and/or Valgrind to look at the details more carefully. You should use the memory debugging tools both on your local machine and by submitting the files to the homework server. Study the memory debugger output carefully. The output should match your understanding of the problems caused by the missing destroy_list implementation. Ask a TA if you have any questions.
Now write and debug the destroy_list function and then re-run the memory debugger (both locally and on the submission server) to show that the memory problems have been fixed. Also finish the implementation of the push_front, pop_front, and pop_back functions.
To complete this checkpoint, show a TA the implementation and memory debugger output before and after writing destroy_list.
Checkpoint 2:
estimate: 20-30 minutes
The PushBack() and the PrintList() function are used in checkpoint2.cpp, but their definitions are missing, please complete these two functions and make sure the program runs and produces the following output.
$ g++ checkpoint2.cpp
$ ./a.out
Linked List of NodeA nodes: 1 -> 2 -> 3 -> 4 -> 5 -> nullptr
Linked List of NodeB nodes: 1 -> 1.41421 -> 1.73205 -> 2 -> 2.23607 -> nullptr
Note: Hardcoding the PrintList() function to just print the above two messages is strictly prohibited. Students doing that will be evicted from the lab room. Also, your functions must be templated functions.
To complete this checkpoint, show a TA the implementation and the output of your program.
Checkpoint 3: Debugging a Merge Sort program.
estimate: 30-40 minutes
We expect our program checkpoint3.cpp to produce the following results when it is compiled and run.
$ g++ checkpoint3.cpp
$ ./a.out
Test Case 1: Original Vector: 5 2 9 1 5 6
Sorted Vector: 1 2 5 5 6 9
Test Case 2: Original Vector: 3 8 2 7 4
Sorted Vector: 2 3 4 7 8
But this program currently does not behave as expected. Troubleshoot this program, find the problems and fix them. You can use a debugger.
To complete this checkpoint, explain to a TA the bugs you found, show a TA your fixes and run the program to show that your fixes are correct and the program now produces the expected results.