Graph Lab 9

gistfile1.cpp

#include <map>
#include <set>
#include <iostream>
#include <string> // Don't know if neccessary...
#include <stdexcept> // Provides the RuntimeError class

using namespace std;

class Graph {
    typedef string NodeName;
    typedef set<NodeName> AdjacencyRow;
    typedef map<NodeName, AdjacencyRow> AdjacencyList;
    
    AdjacencyList adjacency_list;

public:
    bool node_exists(NodeName zname)
    {
        return adjacency_list.count(zname) != 0;
    }

    void add_node(NodeName zname)
    {
        if (node_exists(zname))
            throw runtime_error("Bad! No Duplicates Allowed!");
            
        adjacency_list[zname];
    }
    
    void add_relationship(NodeName zfirst, NodeName zsecond)
    {
        if (!(node_exists(zfirst) && node_exists(zsecond)))
            throw runtime_error("Both nodes must exist!");
            
        adjacency_list[zfirst].insert(zsecond);
        adjacency_list[zsecond].insert(zfirst);
    }
    
    void print(ostream & zout = cout)
    {
        for (AdjacencyList::iterator i = adjacency_list.begin();
             i != adjacency_list.end(); ++i) {
            zout << i->first << ": ";
            for (AdjacencyRow::iterator j = i->second.begin();
                 j != i->second.end(); ++j) {
                zout << *j << " ";
            }
            zout << "\n";
        }
    }
};

int main() {
    Graph graph;
    
    graph.add_node("A");
    graph.add_node("B");
    graph.add_node("C");
    
    graph.add_relationship("A", "B");
    graph.add_relationship("A", "C");
    graph.add_relationship("B", "C");    
    graph.print();
    
    return 0;
}