Comp151: Lab03

Objective:  

global objects and functions

pointers

introduction to a debugger

Download

LinkedList

AssesmentTask

Reference

Data Display Debugger

Lab Work

Create directories  "linkedlist" and "transpose" and "task" under ~/comp151/lab03

Download the zip files to the corresponding folder

unzip the file using command "unzip"
         e.g., unzip LinkedList.zip

List-Accessing Problem

In this problem we are given a linked list of city names

and a sequence of requested accesses :Sydney, Rome, Rome, Rome, Rome, HongKong, Moscow, ... ...

The cost of accessing city is the number of cities that have to be traversed to get to that city. Given a sequence of   requested accesses, our objective is to minimize the cost of accessing the cities in the sequence in the given order.

While processing the accesses we are allowed to modify the list as follows: after accessing a city in the list, we can move it anywhere we want that is closer to the front of the list.

Some algorithms for the problem

Transpose
        --After accessing city 'A', move city 'A' one unit forward towards the front of the list
        --e.g. after accessing Sydney, the list becomes

LinkedList

        --compile LinkedList using the command "gmake"
        --run the program
        --"access.txt" contains a sequence of requested accesses

        --notice how "extern" in main.cpp is used to access the global objects and function.
        --notice how cities are inserted into the list

Transpose

        --List::Insert is now public so as to insert node at run time

        --List::Delete added to delete node at run time

        --compile the program

        --when you run the program, it hangs.

       Let's figure out what happened using the debugger 'ddd'

       -- notice the '-g' parameter in g++

       -- what is memory leak?

    -- what is dangling pointer?

Assessment Task

  Go to the "task" directory in  List.cpp file and complete the implementation  of the functions:

        add your student name, student id, email, and lab section in the very beginning of the file as a comment
          
          place your work

            main.cpp
            List.h
            List.cpp
            resource.h
            resource.cpp
            city.txt
        Makefile

        under ~/comp151/lab03/task

Submission

Our system will collect the files stored under ~/comp151/lab03/task at midnight of the day of your lab.