1D Cellular Automaton /r/programbattles

#include <iostream>
using namespace std;
#define LIVING '#'
#define DEAD '_'
#define TEMPDEAD 'R'
#define TEMPLIVING 'T'
#define BOUND '|'
#define SIZE 22
int mod (int a, int b)
{
   if(b < 0)
     return mod(-a, -b);
   int result = a % b;
   if(result < 0)
     result+=b;
   return result;
}
char *setCell(char grid [], int index, char state)
{
    grid[mod(index,SIZE)]=state;
}
char getCell(char grid [], int index)
{
    return grid[mod(index,SIZE)];
}
char *initializeGrid(char grid [])
{
    for(int i = 0; i < SIZE; i++)
    {
        grid[i] = DEAD;
    }
    setCell(grid,2,LIVING);
    setCell(grid,3,LIVING);
    setCell(grid,4,LIVING);
    setCell(grid,6,LIVING);
    setCell(grid,7,LIVING);
    setCell(grid,9,LIVING);
    setCell(grid,11,LIVING);
    setCell(grid,13,LIVING);
    setCell(grid,15,LIVING);
    setCell(grid,18,LIVING);
    setCell(grid,0,BOUND);
    setCell(grid,SIZE-1,BOUND);
}

void endProgram()
{
    cout << "Press enter to continue..." << endl;
    string input = "";
    getline(cin,input);//keeps console open
}
bool checkifgameover(char grid [], char lastgrid [], int gen)
{
    if(gen>1)
    {
        for(int i = 0; i < SIZE; i++)
        {
            if(grid[i]!=lastgrid[i])
            {
                return false;
            }
        }
        return true;
    }
}
char *updateGrid(char grid [])
{
    for(int i = 0; i < SIZE; i++)
    {
        if(getCell(grid,i)==LIVING)
        {
            if(getCell(grid,i+1) !=LIVING & getCell(grid,i+1) !=BOUND)
            {
                if(getCell(grid,i+2) ==LIVING)
                {
                    setCell(grid,i+1,TEMPLIVING);//WHERE DOES THE POLLEN GO?
                }
            }
            if((getCell(grid,i-1)!=LIVING & getCell(grid,i-1)!=TEMPDEAD ) & (getCell(grid,i+1)!=LIVING & getCell(grid,i-1)!=TEMPDEAD))
            {
                setCell(grid,i,TEMPDEAD);//DEATH BY LONELINESS
            }
            if((getCell(grid,i-1)==LIVING | getCell(grid,i-1)==TEMPDEAD) & (getCell(grid,i+1)==LIVING | getCell(grid,i+1)==TEMPDEAD))
            {
                setCell(grid,i,TEMPDEAD);//DEATH BY OVERPOPULATION
            }
        }
    }
    for(int i = 0; i < SIZE; i++)
    {
        if(getCell(grid,i)==TEMPLIVING)//So no logic is acted on Living cells until after next generation
        {
            setCell(grid,i,LIVING);
        }
        if(getCell(grid,i)==TEMPDEAD)
        {
            setCell(grid,i,DEAD);
        }
    }
}
int main()
{
    char output [SIZE];
    char lastoutput [SIZE];
    initializeGrid(output);
    int generation = 0;
    while(!checkifgameover(output,lastoutput,generation))
    {
        for(int i = 0; i < SIZE; i++)
        {
            lastoutput[i] = output[i];
        }
        generation++;
        cout<< "Current Gen:" << generation;
        for(int i = 0; i < SIZE; i++)
        {
            cout <<  output[i];
        }
        cout << endl;
        updateGrid(output);
    }
    endProgram();
    return 0;
}