Ex. 1. Download the following files:
graph.h
graph.cc
main.cc
Makefile
graph1.txt
graph2.txt
graph3.txt
graph4.txt
graph5.txt
They compile with the command make and the program can be executed with the command graph. The text files contain examples of graphs that can be read by the program.
You will have to implement the 3 functions that have their body missing at the end of the graph.cc file and make some modifications to main.cc. A fourth one can be implemented for extra credit.
a. write . This function should write the graph to a file according to the format described in class and in the notes. You have to make sure that the file is compatible with the read function - meaning that you should be able to read the graph back from the file. You also have to be careful not to write each edge twice if the graph is undirected.
b. input . This function should ask the user if the graph is directed or not, and then for the number of nodes in the graph. After inputting this information, you will need to set the directed flag appropritely and then initialize the graph with that number of vertices, which will assign the names as uppercase letters in sequence. Don't ask the user for the names of the verices, but give them a warning about the way the names were assigned. Then it should input edges in the form first name second name. The input should end with anything that is not an uppercase letter.
c. printBf or printDf. Choose one of these two functions to implement, and let me know in a comment in the submission which one you've chosen. These functions should implement the breadth-first and depth-first traversal of the graph. The operation given in pseudo-code as "processing a node" consists in this case of writing out the name of the vertex. For the printBf you'll need a queue class. You can use either the class from homework 3, of the STL class queue (see http://www.cplusplus.com/reference/queue/queue/ for a reference).
Optional (3 extra credit points): implement both the breadth-first and the depth-first traversal functions above.
d. Modify the menu functions in main.cc by adding the options of writing the graph to a file or to input it from the user.
Turn in: All the files that you modify.