#include <fstream.h>
#include <iostream.h>
#include "sparse.h"

#define n 6

void main() {
  int i;
  int j;

  // declare a sparse array
  SparseArray<double> myArray(n,n,0.0);
  

  // set up its tridiagonal as in the assignment
  for (i=0; i<n; i++) {
    for (j=0; j<n; j++) {
      if (i-j >= -1 && i-j <= 1) {
	myArray.Store(i,j,(i+1)+((double)(j+1)/10));
      }
    }
  }

  // print it out in a dense format
  myArray.WriteDense(cout);
  cout << endl;

  // print it out in a sparse format
  myArray.WriteSparse(cout);
  cout << endl;

  // use iteration to negate its main diagonal
  myArray.SetupIteration(1,2);  // iterate R->L, top->bottom

  myArray.GetCursorPosition(i,j); // get first represented value's position
  while (i != -1) {               // loop until we fall off the array
    if (i == j) {                 // if on the main diagonal
      myArray.Store(i,j,-myArray.Read(i,j));  // negate its value
    }
    myArray.Advance();               // advance the cursor
    myArray.GetCursorPosition(i,j);  // get the next rep value's position
  }

  // print it out again
  myArray.WriteDense(cout);
  cout << endl;

  // print out its density and number of represented elements
  cout << "Density is: " << myArray.Density() << endl;
  cout << "Number of represented elements is: ";
  cout << myArray.NumRepresented() << endl;
}