/* a header file containing the definitions of the class BigInt, used with
   the program readints.cpp
*/

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

class BigInt{
  private:
    /* This is the syntax to have a const data member of a class. */
    static const int NUM_DIGITS = 20;  
    int num[NUM_DIGITS]; 
  public:
    void read_num(ifstream&); /* reads in an integer from the input file */
    void print_num();         /* prints out the integer to the screen */
  //    BigInt sum(BigInt);       /* You should implement this function below. */
};

void BigInt::read_num(ifstream& infile){

  int a[NUM_DIGITS], i,j;
  char inp;

  /* skip everything before the first integer starts */
  do
    infile.get(inp);         // similar to infile >> inp, but doesn't
                             // skip over white space.
  while (inp<'0' || inp>'9');  

  a[0] = inp - '0';

  for(i=1; i<NUM_DIGITS; i++){
    infile.get(inp);
    if (!infile.eof() && '0' <= inp && inp <= '9')
      a[i] = inp - '0';
    else
      break;
  }
  /* Now i is the number of digits of the integer. */

  /* Reverse the order of the digits. */
  for(j=0; j<i; j++)
    num[j] = a[i-1-j];

  /* Fill out any initial digits to be 0. */
  for(j=i; j<NUM_DIGITS; j++)
    num[j] = 0;
}

void BigInt::print_num(){

  bool initialzero = true;
 
  /* We don't want to print out initial zeroes of our number, the variable
     initialzero controls this.
  */

  for(int i=NUM_DIGITS-1; i>=0; i--){
    if (num[i])
      initialzero = false;
    if (!initialzero || i==0)
      cout << static_cast<char>(num[i]+'0');
  }
}