Dynamic array error in Conways Game of Life - c++

Question

I am working on a program that emulates conways game of life, and it works perfectly with the preset dimensions. However, once i try to use the dynamic dimensions as seen in option e, i start having problems. The main problem is in the "life" function which iterates throughout the array and decides if it should bring to life a cell. I have been debugging for a while and it i enter the dimensions as 50*40, it iterates until 61, 1. This should technically work but it just breaks everytime. Keep in mind that I add 12 to each dimension to account for the buffer zone I put around the edges. Technically it should work then right? If you have any suggestions I would really appreciate it!
#include <iostream>
#include <string>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <new> // i havent used this one yet
#include <cmath>
using namespace std;
// REMEMBER: The outside of the array is 6 more than what we show so that nothing interferes
//also that it goes y,x and that x is going to be bigger so that we get a rectange
//we use the copy function to copy an array from eachother, either the current one to the temp one or
//vise versa. This is so that we can alter the cells one step at a time without affecting everything else.
void copy(int **array1, int **array2, int o, int p)
{
for(int j = 0; j < o; j++)
{
for(int i = 0; i < p; i++)
array2[j][i] = array1[j][i];
}
} // the second array sent is assigned the first array sent!
//this array will initialize our arrays so that we can use them later
int** init(int n, int m)
{
int **array;
array = new int*[m]; // x
array = new int*[n]; // y
for (int q=0; q < n; q++)
{
array[q] = new int[n];
for (int w=0; w < m; w++)
{
array[w] = new int[m];
}
}
return array;
}
void populate(int o, int p, int** board){ // THIS FUNCTION HASN'T BEEN USED YET
for(int i=0; i < p; i++)
{
for(int j=0; j < o; j++) // It was in a in-class demo but i dont think i need it
{
board[i][j] = pow(i, j);
}
}
}
//The life function looks at the pieces around the cell and figures out what happens next.
// Probably the most important in the entire program, feast your eyes!
void life(int **array, int o, int p)
{
//Copies the main array to a temp array so changes can be made without affecting anyone else
int **temp;
temp = init(o, p);
copy(array, temp, o, p);
for(int j = 1; j < o; j++)
{
for(int i = 1; i < p; i++)
{
// checks all 8 cells surrounding it
int count = 0;
cout << " j is " << j << " and i is " << i << endl;
// cout << array[j][i]; // DEBUGGING
count =
array[j-1][i] + array[j-1][i-1] +
array[j][i-1] + array[j+1][i-1] +
array[j+1][i] + array[j+1][i+1] +
array[j][i+1] + array[j-1][i+1];
//cell dies.
if(count < 2 || count > 3)
{
temp[j][i] = 0;
}
//nothing happens.
if(count == 2)
{
temp[j][i] = array[j][i];
}
//now the cell will be born, or if it already is alive then it stays that way.
if(count == 3)
{
temp[j][i] = 1;
}
}
}
//Copies the temp array back to the main array.
copy(temp, array, o, p);
}
//This function prints the 40 x 50 part of the array, a 1 means that there will be a cell there,
//otherwise it will just be an empty space.
void print(int **array, int o, int p)
{
// WE ONLY CHECK WHAT WE SEE, WHICH IS 6 LESS THAN THE ARRAY!!!
for(int j = 6; (j < (o-6)); j++)
{
for(int i = 6; (i < (p-6)); i++)
{
if(array[j][i] == 1 )
cout << '*';
else
cout << '.';
}
cout << endl;
}
}
//I read somewhere it would be a good idea to make sure to end the program early if it somehow
//became stable by itself early. so this compares the old array with the new one to check if they
//are the same. This commonly occurs if a glider runs off the screen for example.
bool compare(int **array1, int **array2,int o,int p)
{
int counter = 0;
for(int j = 0; j < o; j++)
{
for(int i = 0; i < p; i++)
{
if(array1[j][i]==array2[j][i])
counter++;
}
}
if(counter == o*p)
return true;
else
return false;
}
int main()
{
int o= 52, p=62;
int **firstgen;
int **next;
int **backup;
// 40 + 12, 50 + 12
int x, y;
char starty;
char again;
char cont;
bool comparison;
//Here is where we initialize our arrays
firstgen = init(o,p);
next = init(o,p);
backup = init(o,p);
cout << endl << "Welcome to John Conway's Game of Life." << endl;
//This loop is for if we are still simulating, don't get confused!
do
{
//this loop checks for inputs.
do
{
menu: //this is a goto we use for if we change dimensions
x = 0, y = 0;
//now we get the menu
cout << endl << "--- Choose an option Below ---" << endl;
cout << "(a) Glider" << endl;
cout << "(b) Gosper Gilder gun" << endl;
cout << "(c) R Pentomino Pattern" << endl;
cout << "(d) Oscillator" << endl;
cout << "(e) Change the dimensions (it defaults to (50*40)" << endl;
cin >> starty;
}while(starty != 'a' && starty != 'b' && starty != 'c' && starty != 'd' && starty != 'e');
int i = 0;
//we need to assign firstgen in this area
//choose a glider position
if (starty == 'a'){
x= 0, y= 0;
cout << " X dimension: ";
cin >> x;
cout << " Y dimension: ";
cin >> y;
if (x < 0 || x > p || y < 0 || y > o){
cout << endl << "you entered invalid dimensions" << endl;
goto menu;
}
x = x+6; //we add 6 because there are six spots to the left that aren't shown we need to account for
y = y+6;
//creates the glider
firstgen[y][x] = 1;
firstgen[y][x+1] = 1;
firstgen[y][x+2] = 1;
firstgen[y-1][x] = 1;
firstgen[y-2][x+1] = 1;
}
else if (starty == 'b'){
x= 0, y= 0;
cout << "Your dimensions are based on the farthest left point" << endl;
cout << " X dimension: ";
cin >> x;
cout << " Y dimension: ";
cin >> y;
if (x < 0 || x > p || y < 0 || y > o){
cout << endl << "you entered invalid dimensions" << endl;
goto menu;
}
//this is because we have the buffer zone of 6
x = x+6;
y = y+6;
//Gosper gun
//box on left
firstgen[y][x] = 1;
firstgen[y][x+1] = 1;
firstgen[y+1][x] = 1;
firstgen[y+1][x+1] = 1;
//left circle starting in top of the left curve (flat part)
firstgen[y][x+10] = 1;
firstgen[y-1][x+11] = 1;
firstgen[y-2][x+12] = 1;
firstgen[y-2][x+13] = 1;
firstgen[y+1][x+10] = 1;
firstgen[y+2][x+10] = 1;
firstgen[y+3][x+11] = 1;
firstgen[y+4][x+12] = 1;
firstgen[y+4][x+13] = 1;
//dot in middle
firstgen[y+1][x+14] = 1;
//arrow thing on the right
firstgen[y-1][x+15] = 1;
firstgen[y][x+16] = 1;
firstgen[y+1][x+16] = 1;
firstgen[y+1][x+17] = 1;
firstgen[y+2][x+16] = 1;
firstgen[y+3][x+15] = 1;
//boomerang bit on the far right section
firstgen[y][x+20] = 1;
firstgen[y][x+21] = 1;
firstgen[y-1][x+20] = 1;
firstgen[y-1][x+21] = 1;
firstgen[y-2][x+20] = 1;
firstgen[y-2][x+21] = 1;
firstgen[y-3][x+22] = 1;
firstgen[y-3][x+24] = 1;
firstgen[y-4][x+24] = 1;
firstgen[y+1][x+22] = 1;
firstgen[y+1][x+24] = 1;
firstgen[y+2][x+24] = 1;
//tiny box on farthest right, almost done!
firstgen[y-1][x+34] = 1;
firstgen[y-1][x+35] = 1;
firstgen[y-2][x+34] = 1;
firstgen[y-2][x+35] = 1;
}
else if (starty == 'c')
{
x= 0, y= 0;
cout << "Your dimensions are based on the farthest left point" << endl;
cout << " X dimension: ";
cin >> x;
cout << " Y dimension: ";
cin >> y;
if (x < 0 || x > p || y < 0 || y > o){
cout << endl << "you entered invalid dimensions" << endl;
goto menu;
}
x = x+6;
y = y+6;
//creates R Pentamino pattern
firstgen[y][x] = 1;
firstgen[y][x+1] = 1;
firstgen[y+1][x+1] = 1;
firstgen[y-1][x+1] = 1;
firstgen[y-1][x+2] = 1;
}
// creates the simple oscillator
else if (starty == 'd')
{
x= 0, y= 0;
cout << "Your dimensions are based on the top of the oscillator" << endl;
cout << " X dimension: ";
cin >> x;
cout << " Y dimension: ";
cin >> y;
if (x < 0 || x > p || y < 0 || y > o){
cout << endl << "you entered invalid dimensions" << endl;
goto menu;
}
x = x+6;
y = y+6;
firstgen[y][x] = 1;
firstgen[y+1][x] = 1;
firstgen[y+2][x] = 1;
}
// allows you to choose your dimensions
else if (starty == 'e')
{
o= 0, p= 0;
x= 0, y= 0;
cout << "choose the height and width of your field, between 0 and 100" << endl;
cout << " X dimension: ";
cin >> x;
cout << " Y dimension: ";
cin >> y;
if (x < 0 || x > 100 || y < 0 || y > 100){
cout << endl << "Please keep dimensions between 0 and 100" << endl;
goto menu;
}
// the problem is that it is adding my x dimension and my placement choice together and then
// starts to run the program, which threadbreaks. I need to find out why these two values are
// adding together and fix it
x = x+12;
y = y+12; // plus twelve so that we have 6 around all sides
p = x;
o = y;
firstgen = init(o,p);
next = init(o,p);
backup = init(o,p);
// is this part below necessary?
//firstgen[o][p];
// next[o][p];
// backup[o][p];
// idk
// cout << "y value is: " << o << " and the x value is " << p << endl; // debugging
goto menu;
}
//Loop that does the simulation.
do
{
//Prints the generation. If i == 0, the firstgen array is copied to the
//next array, and is printed before any functions act upon it.
cout << endl << "Generation " << i << ":" << endl << endl;
//Initializes the arrays by copying the firstgen array to the next array.
if(i == 0)
copy(firstgen, next, o, p);
//this stuff below happens in every cycle
cout << "the x/p value is" << p << "and the y/o value is " << o << endl;
copy(next, backup, o, p);
print(next, o, p);
life(next, o, p);
i++;
//Pauses the system .2 seconds so that it doesn't flash past you super fast and you
// can't appreciate its beauty
system("sleep .2");
//Checks whether the generation is a multiple of 100 to ask
//the user if they want to continue
if(i % 100 == 1 && i != 1)
{
cout << endl;
//Loop to check for proper inputs.
do
{
cout << "Continue? (y or n): ";
cin >> cont;
}while(cont != 'y' && cont != 'n');
if(cont == 'n')
break;
}
//Compares the current generation with a backup generation.
//The idea is that if it is the same with the backup generation then
//something boring is going on or smething went wrong. It will end if that
//is the case.
comparison = compare(next, backup, o, p);
if(comparison == false)
// system("clear");
//cout << string( 10, '\n' );
if(comparison == true)
cout << endl;
}while(comparison == false);
//Loop to check if we want to keep going.
do
{
cout << "Run another Simulation? (y or n): ";
cin >> again;
}
while(again != 'y' && again != 'n');
//this is where we clean out all our firstgen values
//i used to have this at the top but didn't really need it
for(int y = 0; y < o; y++)
{
for(int x = 0; x < p; x++)
{
firstgen[y][x] = 0;
}
}
}
while(again == 'y');
return 0;
}

Answer 1

I figured it out!
The thing to take away from this is to make sure that your initiation function creates the array with the same size as the one you will be accessing. I was trying to get values from array[52][1] which didn't exist because in my init function i only had the for loop running while n < o, which means it didn't create the 52nd row. what a relief!