#include <stdio.h>
#include <stdlib.h>

unsigned int calculate_area(int **_field, unsigned int _size_x, unsigned int _size_y, unsigned int _x, unsigned int _y) {
	unsigned const int min_x = _x == 0 ? 0 : _x - 1;
	unsigned const int max_x = _x == _size_x - 1 ? _x : _x + 1;
	
	unsigned const int min_y = _y == 0 ? 0 : _y - 1;
	unsigned const int max_y = _y == _size_y - 1 ? _y : _y + 1;
	
	unsigned int area_sum = 0;

	for ( unsigned int x = min_x; x <= max_x; x++ ) {
		for ( unsigned int y = min_y; y <= max_y; y++ ) {
			area_sum += _field[x][y];
		}
	}

	area_sum -= _field[_x][_y];

	return area_sum;
}

void iterate(int **_field, unsigned int _size_x, unsigned int _size_y) {
	int **next_generation = NULL;

	next_generation = malloc( sizeof( *next_generation ) * _size_x );
	for ( unsigned int x = 0; x < _size_x; x++ ) {
		next_generation[x] = malloc( sizeof( **next_generation ) );
	}

	for (unsigned int x = 0; x < _size_x; x++) {
		for (unsigned int y = 0; y < _size_y; y++) {
			unsigned int surrdounding_count = calculate_area(_field, _size_x, _size_y, x, y);
			if (surrdounding_count < 2 || surrdounding_count > 3)
				next_generation[x][y] = 0;
			else
				next_generation[x][y] = 1;
		}
	}

	for (unsigned int x = 0; x < _size_x; x++) {
		for (unsigned int y = 0; y < _size_y; y++) {
			_field[x][y] = next_generation[x][y];
		}
	}

	for ( unsigned int x = 0; x < _size_x; x++ ) {
		free (next_generation[x]);
	}
	free(next_generation);
}

int main(void) {

	int **field = NULL;

	unsigned const int size_x = 3;
	unsigned const int size_y = 3;

	field = malloc( sizeof( *field ) * size_x );
	for ( unsigned int x = 0; x < size_x; x++ ) {
		field[x] = malloc( sizeof( **field ) );
	}

	for (unsigned int x = 0; x < size_x; x++) {
		for (unsigned int y = 0; y < size_y; y++) {
			field[x][y] = x == y ? 1 : 0;
		}
	}
	unsigned int gen_cnt = 0;
	while ( 1 ) {
		printf("\n\nGeneration %i\n", gen_cnt);
		for (unsigned int x = 0; x < size_x; x++) {
			for (unsigned int y = 0; y < size_y; y++) {
				printf("%c", field[x][y] ? 'X' : ' ');
			}
			printf("\n");
		}
		
		gen_cnt ++;
		iterate(field, size_x, size_y);
	}

	return 0;
}