CSCI 1120 (Low-Level Computing), Fall 2017:
Homework 8

Credit:
25 points.

Reading

Be sure you have read, or at least skimmed, the assigned readings for classes through 11/01.

Honor Code Statement

Please include with each part of the assignment the Honor Code pledge or just the word ``pledged'', plus one or more of the following about collaboration and help (as many as apply).1Text in italics is explanatory or something for you to fill in. For written assignments, it should go right after your name and the assignment number; for programming assignments, it should go in comments at the start of your program(s).

Programming Problems

Do the following programming problems. You will end up with at least one code file per problem. Submit your program source (and any other needed files) by sending mail to bmassing@cs.trinity.edu with each file as an attachment. Please use a subject line that mentions the course and the assignment (e.g., ``csci 1120 hw 8'' or ``LL hw 8''). You can develop your programs on any system that provides the needed functionality, but I will test them on one of the department's Linux machines, so you should probably make sure they work in that environment before turning them in.

  1. (25 points) Your mission for this assignment is to complete a partial implementation in C of a binary search tree (a.k.a. sorted binary tree) of ints. (I'm hoping that all of you know about this data structure from CS2 or another course. If not, the Wikipedia articles a reasonable description (but I recommend that you not read the example code until/unless you try to write your own).

    This partial implementation consists of a number of files:

    I've made a ZIP file containing all of these files, so it will probably be simplest just to download that and unzip it (command unzip on our machines). If you prefer to download individual files, NOTE that you should use your browser's ``download'' or ``save'' function to obtain the Makefile rather than copying and pasting text. This is because copy-and-paste will likely replace the tab characters in the file with spaces, with bad consequences (since tabs are semantically significant in makefiles.)

    Your job is to modify the file int-bst.c so it includes function definitions for all the functions declared in int-bst.h. The test program is self-contained and contains code to call the functions you will write, so you don't need to write any input/output code, aside from implementing two print functions. You compile the test program by typing make test-int-bst and run it by typing test-int-bst.

    Notice that the function that removes a single element of the tree (int_bst_remove) is optional -- you can provide an ``implementation'' that just prints an error message, or for extra credit you can actually implement this operation.

    You should not modify any other files, unless you want to add additional tests to test-int-bst.c.

    Sample output of the test program:

    inserting 40 into tree [ ]
    result [ 40 ]
    inserting 30 into tree [ 40 ]
    result [ 30 40 ]
    inserting 50 into tree [ 30 40 ]
    result [ 30 40 50 ]
    inserting 20 into tree [ 30 40 50 ]
    result [ 20 30 40 50 ]
    inserting 60 into tree [ 20 30 40 50 ]
    result [ 20 30 40 50 60 ]
    inserting 16 into tree [ 20 30 40 50 60 ]
    result [ 16 20 30 40 50 60 ]
    inserting 14 into tree [ 16 20 30 40 50 60 ]
    result [ 14 16 20 30 40 50 60 ]
    inserting 18 into tree [ 14 16 20 30 40 50 60 ]
    result [ 14 16 18 20 30 40 50 60 ]
    inserting 24 into tree [ 14 16 18 20 30 40 50 60 ]
    result [ 14 16 18 20 24 30 40 50 60 ]
    inserting 56 into tree [ 14 16 18 20 24 30 40 50 60 ]
    result [ 14 16 18 20 24 30 40 50 56 60 ]
    inserting 64 into tree [ 14 16 18 20 24 30 40 50 56 60 ]
    result [ 14 16 18 20 24 30 40 50 56 60 64 ]
    inserting 30 into tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result [ 14 16 18 20 24 30 40 50 56 60 64 ]
    inserting 50 into tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result [ 14 16 18 20 24 30 40 50 56 60 64 ]
    test data in order [ 14 16 18 20 24 30 30 40 50 50 56 60 64 ]
    40
      30
          20
              16
                  14
                      .
                      .
                  18
                      .
                      .
              24
                  .
                  .
          .
      50
          .
          60
              56
                  .
                  .
              64
                  .
                  .
    finding 0 in tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result false
    finding 100 in tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result false
    finding 10 in tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result false
    finding 40 in tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result true
    finding 14 in tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result true
    finding 64 in tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result true
    removing 0 from tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result [ 14 16 18 20 24 30 40 50 56 60 64 ]
    removing 16 from tree [ 14 16 18 20 24 30 40 50 56 60 64 ]
    result [ 14 18 20 24 30 40 50 56 60 64 ]
    removing 60 from tree [ 14 18 20 24 30 40 50 56 60 64 ]
    result [ 14 18 20 24 30 40 50 56 64 ]
    removing 30 from tree [ 14 18 20 24 30 40 50 56 64 ]
    result [ 14 18 20 24 40 50 56 64 ]
    removing 50 from tree [ 14 18 20 24 40 50 56 64 ]
    result [ 14 18 20 24 40 56 64 ]
    40
      20
          14
              .
              18
                  .
                  .
          24
              .
              .
      64
          56
              .
              .
          .
    inserting 0 into tree [ 14 18 20 24 40 56 64 ]
    result [ 0 14 18 20 24 40 56 64 ]
    inserting 100 into tree [ 0 14 18 20 24 40 56 64 ]
    result [ 0 14 18 20 24 40 56 64 100 ]
    inserting 0 into tree [ 0 14 18 20 24 40 56 64 100 ]
    result [ 0 14 18 20 24 40 56 64 100 ]
    inserting 100 into tree [ 0 14 18 20 24 40 56 64 100 ]
    result [ 0 14 18 20 24 40 56 64 100 ]
    after removing all elements [ ]
    

    Hints:

    What to turn in: Just send me your int-bst.c file, unless you added more tests to test-int-bst.c, in which case send that too (but be sure your code works with the provided version as well).



Footnotes

... apply).1
Credit where credit is due: I based the wording of this list on a posting to a SIGCSE mailing list. SIGCSE is the ACM's Special Interest Group on CS Education.


Berna Massingill
2017-11-20