I'm trying to implement the game of life in c++ but I've run in to some trouble where I don't get the correct result.
I think the problem is with memcpy() as it seems to mess up the arrays but I'm not sure why. If I just copy the two different arrays using nested for loops I get a different result which is also wrong.

[source lang="cpp"]#include <iostream>
#include <conio.h>
#include <string>

void update();
void init();
int calcNeighbours(int i, int j);
void draw();

bool run = true;
bool field[20][20];

int main()
{
init();
draw();
getch();
while(run)
{
update();
draw();
getch();
}
return 0;
}

void update()
{
int temp = 0;
int tf[20][20];

memcpy(tf,field,sizeof(tf));

for(int i = 0;i<20;i++)
{
for(int j = 0;j<20;j++)
{
temp = calcNeighbours(i,j);
if(field[j]==true && temp < 2)
{
tf[j] = false;
}
else if(field[j]==true && temp > 3)
{
tf[j] = false;
}
else if(field[j]==true && (temp == 2 || temp == 3))
{
tf[j] = true;
}
else if(field[j]==false && temp == 3)
{
tf[j] = true;
}
}
}

memcpy(field,tf,sizeof(field));

}

void init()
{
for(int i = 0;i<20;i++)
{
for(int j = 0;j<20;j++)
{
field[j] = false;
}
}

field[3][5] = true;
field[4][5] = true;
field[5][5] = true;
field[4][4] = true;
field[4][6] = true;

}

int calcNeighbours(int i, int j)
{
int temp = 0;

for(int a = -1;a<1;a++)
{
for(int b = -1;b<1;b++)
{
if(field[i-a][j-b] == true)
temp+=1;
}
}
return temp;
}

void draw()
{
system("cls");
for(int i = 0;i<20;i++)
{
std::cout<<std::endl;
for(int j = 0;j<20;j++)
{
if(field[j]==true)
std::cout<<"X";
else
std::cout<<" ";
}
}
}[/source]

You have defined field as an array of booleans and tf as an array of integers. They have different types and probably also different sizes.

Thanks, now the copying works. I still got a problem with the figures being wrong. Somewhere I do something wrong with the rules of game of life or calculating the neighbors but I cant find where.

I found what I did wrong, in calcNeighbors when I loop I wrote <1 instead of <=1.