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

#define SPACE 1920
#define TIME 1080

typedef int state;

void randomise(state* array) {
	int i;
	for(i=0; i<SPACE; i++) array[i] = rand() % 2;
	return;
}

void print_pbm_header() {
	printf("P1\n");
	printf("%d %d\n", SPACE, TIME);
	return;
}

void print_step(state* step) {
	int i;
	for(i=0; i<(SPACE-1); i++) printf("%d ", step[i]);
	printf("%d\n", step[SPACE-1]);
	return;
}

void next_step(state* current, state* previous) {
	int i;
	for(i=0; i<SPACE; i++) previous[i] = current[i];

	current[0] = previous[1];
	current[SPACE-1] = previous[SPACE-2];

	for(i=1; i<(SPACE-1); i++) current[i] = previous[i-1] ^ previous[i+1];

	return;
}

int main() {
	state* current = calloc(SPACE, sizeof(state));
	assert(current);
	state* previous = calloc(SPACE, sizeof(state));
	assert(previous);
	
	print_pbm_header();

	srand((unsigned int)time(NULL));
	randomise(current);
	print_step(current);

	int i;
	for(i=1; i<TIME; i++) {
		next_step(current, previous);
		print_step(current);
	}

	free(current);
	free(previous);

	return 0;
}