//
//  Sloppy I/O Routines for Assignment 4
//     free of charge from Prof. Rogaway!
//  

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream.h>
#include <ctype.h>
#include <fstream.h>
#include <libc.h>

//---------------------------------------------------------------------------
// abort -
//   Utility routine that outputs an error message and exits.
//---------------------------------------------------------------------------
void abort(char* s)
{
    cerr << "Error occurred, aborting." << endl;
    if (s != 0)
        cerr << s << endl;
    exit(1);
}

//---------------------------------------------------------------------------
// Graph -
//    a very simple Graph class, supporting a constructor which reads in 
//    a graph and forms an adjaceny list, and member functions to get
//    the number of verticies, the name of each vertex, and the length
//    of each edge.  Verticies are referred to by numbers 0,1,..., n-1.
//---------------------------------------------------------------------------
 
class Graph {
  int n;          // number of verticies;
  double **Adj;   // n x n adjacency matrix
  char** names;   // "names" for the n verticies
public:
  Graph(const char* ="\0"); // constructor. If no argument, read std input
  int numnodes() {return n;};   // accessor function -- number of verticies
  char* name(int i)             // returns the "name" of vertex i
     {if (i<0 || i>=n) abort("Bad argument to graph::name");
      return names[i];}; 
  double length(int i, int j) // returns the length of edge (i,j)
     {if (i<0 || i>= n || j<0 || j>=n) abort("Bad argument to graph::length");
      return Adj[i][j];}; 
};

//---------------------------------------------------------------------------
// Graph::Graph -
//   constructor -- reads in n and then n lines of data, each containing
//   a vertex "name" and a (latitude, longitude) on the earth's surface.
//---------------------------------------------------------------------------
Graph::Graph(const char* name)
{
  const n_max = 100;
  char line[80];
  double *latitude, *longitude;
  int i,j;
  double dist_earth(double, double, double, double);

  ifstream infile(name);
  if (name[0] && !infile) abort("Can't open input file");

  if (name[0]) infile.getline(line,sizeof(line));
  else            cin.getline(line,sizeof(line));
  if (sscanf(line, "%d", &n)!=1) abort("Bad input file");

  latitude  = new double[n];
  longitude = new double[n];
  names = new char*[n];
  Adj = new double*[n];
  for (i=0; i<n; i++) {
    Adj[i] = new double[n];
  } 

  for (i=0; i<n && i<n_max; i++) {
    if (name[0]) infile.getline(line,sizeof(line));
    else            cin.getline(line,sizeof(line));
    j = 0;
    do 
      j++; 
    while (j<80 && !isdigit(line[j]));
    if (sscanf(line+j, "%lf %lf", &latitude[i], &longitude[i]) !=2)
      abort("Bad input file");
    do
      j--;
    while (j && isspace(line[j]));
    line[j+1] = '\0'; 
    names[i] = new char[j+1];
    strcpy (names[i], line); 
  }
  
  for (i=0; i<n; i++) {
    for (j=0; j<n; j++) {
       Adj[i][j] = dist_earth(latitude[i],longitude[i],
                              latitude[j],longitude[j]);
    }
  }
}

//---------------------------------------------------------------------------
// operator<< (ostream, Graph)
//   prints adjacency matrix of a graph to standard output
//---------------------------------------------------------------------------
ostream& operator<< (ostream& os, Graph& G)
{
  int i,j;
  if (os!=cout) abort("Only know how to ouput graphs to cout");
  printf("               ");
  for (j=0; j<G.numnodes(); j++) printf("%.4s ",G.name(j));
  printf("\n");
  printf("               ");
  for (j=0; j<G.numnodes(); j++) printf("---- ");
  printf("\n");

  for (i=0;  i<G.numnodes(); i++) {
    printf("%14s ", G.name(i));
    for (j=0; j<G.numnodes(); j++) {
      printf("%4.0f ",G.length(i,j));
    }
    printf("\n");
  }
  return os;
}






//---------------------------------------------------------------------------
// main
//---------------------------------------------------------------------------
int main(int argc, char* argv[])
{
  if (argc==1) {Graph G;          cout<< G;}
          else {Graph G(argv[1]); cout<<G;}
}