Laboratory 2 Solutions

CSCI 132 Data Structures--Spring 2014

Laboratory 2 Solutions
Solution to life1.cc code:
/*******************************************************************
* Name: Brenda Student
* Date: 1/28/14
* Course: CSCI 132
* Assignment: Lab2
* Instructor: Royden
* Program: life1.cc
* Purpose: Implementation of Life class with wrap around grid.
********************************************************************/
#include "life1.h"

int Life::neighbor_count(int row, int col)
  /*
Pre:  The Life object contains a configuration, and the coordinates
      row and col define a cell inside its hedge.
Post: The number of living neighbors of the specified cell is returned.
  */

{
  int i, j;
  int nrow, ncol;
  int count = 0;
  for (i = row - 1; i <= row + 1; i++)
    for (j = col - 1; j <= col + 1; j++) {
      nrow = i;
      ncol = j;
      if (i < 0) {
        nrow = maxrow - 1;
      }
      if (j < 0) {
        ncol = maxcol-1;
      }
      if ( i >= maxrow ) {
        nrow = 0;
      }
      if (j >= maxcol) {
        ncol = 0;
      }
  
      count += grid[nrow][ncol];  //  Increase the count if neighbor is alive.
    }
  count -= grid[row][col]; //  Reduce count, since cell is not its own neighbor
  return count;
}


void Life::update()
  /*
Pre:  The Life object contains a configuration.
Post: The Life object contains the next generation of configuration.
  */

{
  int row, col;
  int new_grid[maxrow][maxcol];

  for (row = 0; row < maxrow; row++)
    for (col = 0; col < maxcol; col++)
      switch (neighbor_count(row, col)) {
      case 2:
        new_grid[row][col] = grid[row][col];  //  Status stays the same.
        break;
      case 3:
        new_grid[row][col] = 1;                //  Cell is now alive.
        break;
      default:
        new_grid[row][col] = 0;                //  Cell is now dead.
      }


  for (row = 0; row < maxrow; row++)
    for (col = 0; col < maxcol; col++)
      grid[row][col] = new_grid[row][col];
}




void Life::initialize()
  /*
Pre:  None.
Post: The Life object contains a configuration specified by the user.
  */

{
  int row, col;
  for (row = 0; row < maxrow; row++)
    for (col = 0; col < maxcol; col++)
      grid[row][col] = 0;
  cout << "List the coordinates for living cells." << endl;
  cout << "Terminate the list with the special pair -1 -1" << endl;
  cin >> row >> col;

  while (row != -1 || col != -1) {
    if (row >= 1 && row <= maxrow)
      if (col >= 1 && col <= maxcol)
        grid[row-1][col-1] = 1;
         else
           cout << "Column " << col << " is out of range." << endl;
      else
        cout << "Row " << row << " is out of range." << endl;
    cin >> row >> col;
  }
}

void Life::print()
  /*
Pre:  The Life object contains a configuration.
Post: The configuration is written for the user.
  */

{
  int row, col;
  cout << "\nThe current Life configuration is:" << endl;
  for (row = 0; row < maxrow; row++) {
    for (col = 0; col < maxcol; col++)
      if (grid[row][col] == 1) cout << '*';
      else cout << ' ';
    cout << endl;
  }
  cout << endl;
}