I am writing a program that will build a graph and then find the lowest costs between any given vertices. I have the program building the graph just fine, but now I just started to write the part that will find lowest costs and I get a seg fault error. After using cout's I have found that the entire program will run. But then right at the end when it should end, it suddenly hits a seg fault. Right now I am thinking it has something to do with the initialize function since this problem occured when that function was written. Any ideas? Thanks.

// Main program
#include <iostream>
#include "graph.cc"
using namespace std;

main ()
{
 
  graph flightfares;
  flightfares.build_graph();
  flightfares.print_graph();
  flightfares.find_shortest_dist();
  // My program will get right here then hit seg fault
}






// Class and implementation program 
// graph.cc
#include <iostream>
#include <vector>
#include <string>
#include <float.h>
using namespace std;




struct costpair
  {
    int vnum;
    float fare;
    costpair(int v = 0, float f = 0):vnum(v), fare(f){};
  };





struct node
  {
    costpair info;
    node * next;
  };





class graph
  {
    public:
      graph();
      ~graph();
      void build_graph();
      void print_graph();
    void find_shortest_dist();



    private:
      // Attributes
      vector<string> vnames;
      vector<node*> adjlist;
    double dist[];
    int pred[];
    bool undecided[];

      // Member functions
      int index(string name);
      void insert_edge(string name1, string name2, float fare);
      int add_vertice(string name);
      void add_edge(int index1, costpair temp);
      node * createnode(costpair temp);
    void initialize();
  };

// Constructor
graph::graph()
{

}




// Destructor
graph::~graph()
{
  for (int i = 0; i < vnames.size(); i++)  // This loop will run and delete all lists
    {
      node * p = adjlist.at(i);
      node * temp;
      while (p!=NULL)
        {
          temp = p->next;  // Saves pointer to rest of list
          delete p;
          p = temp;
        }
    } 
}



void graph::build_graph()
  {
    string name1, name2;
    int index1, index2;
    float fare;

    cin >> name1 >> name2 >> fare;  //Priming Read
    while(name1 != "zzz") // Runs till end of file
      {
        insert_edge (name1, name2, fare);

        // This if checks for EOF and reads next line if present
        if(!(cin >> name1 >> name2 >> fare))
          {
            break;
          }
       }
  }




// Returns the index of given name
int graph::index(string name)
  {
    for (int i = 0; i < vnames.size(); i++)
      {
        if (vnames.at(i) == name)   return i;
      }

    return (-1); // Name was not found
}



// Function to insert new edge
// Called once two names and a fare have been read
void graph::insert_edge(string name1, string name2,
float fare)
  {
    int index1 = index(name1);
    // Next if checks if first name needs to be added
    if (index1 == -1) index1 = add_vertice(name1);  
    int index2 = index(name2);
    // Next if checks if second name needs to be added
    if (index2 == -1) index2 = add_vertice(name2);
    // At this point, index1 and index2 contain the indices of name1 and name2

    // This adds the edge
    add_edge(index1, costpair(index2, fare));
}




// This functin addes a name to the name vector
// and pushes the adjacency vector back.
// Then the new index of the name is returned
int graph::add_vertice(string name)
  {
    vnames.push_back(name);
    adjlist.push_back(NULL);
    return (vnames.size()-1);
  }




//  Here a node is added to the adjacency vector
void graph::add_edge(int index1, costpair temp)
  {
    node * p = createnode(temp);  // Creates node

    // Adds node to appropriate list 
    p->next = adjlist.at(index1);
    adjlist.at(index1) = p;

  }



// This function creates a node and adds info to node
node * graph::createnode(costpair temp)
  {
    node * p = new node;
    p->info = temp;
    p->next = NULL;
    return p;
  }



// This fuction prints all vertices along with edges
void graph::print_graph()
  {
    for (int i = 0; i < vnames.size(); i++) // Runs for all vertices
      {
        cout << "The vertex is " << vnames.at(i) << endl;
        node * p = adjlist.at(i);  // Pointer to traverse list
        if (p == NULL)  // Checks if list is empty or not
          {
            cout << "This vertex has no neighbors" << endl;
          }
        else
          {
            cout << "The neighbors of this node are " << endl;
            while (p!=NULL)
              {
                cout << vnames.at(p->info.vnum) << "(" << p->info.fare << ")" << endl;
                p = p->next;          
              }
           }
        }
  }






void graph::find_shortest_dist()
{
  initialize();  // Will initialize the several arrays needed

}


void graph::initialize()
{
  dist[vnames.size()];
  pred[vnames.size()];
  undecided[vnames.size()];


  for (int i = 0; i < vnames.size(); i++)
    {
      dist[i] =  DBL_MAX;
      pred[i] = -1;
      undecided[i]= false;
    }
}

I had a feeling my grasp of declaring the arrays was the problem. Could anyone tell me why the seg fault occured though after the entire program ran instead of when it hit that bad code?

main ()
{
 
  graph flightfares;
  flightfares.build_graph();
  flightfares.print_graph();
  flightfares.find_shortest_dist();
  // My program will get right here then hit seg fault
}
void graph::find_shortest_dist()
{
  initialize();  // Will initialize the several arrays needed

}
void graph::initialize()
{
  dist[vnames.size()];
  pred[vnames.size()];
  undecided[vnames.size()];
  undecided[vnames.size()];

  for (int i = 0; i < vnames.size(); i++)
    {
      [B]dist[i] =  DBL_MAX;[/B]

My guess would be right about here -- right where you say it does.

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