Quick and dirty implementation of Conway's Game of Life in C

gameoflife.c

#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>

int main (void)
{
    struct winsize w;
    ioctl(0, TIOCGWINSZ, &w);
    int cols = w.ws_col - 1;
    int rows = (w.ws_row - 1) * 2;
    int i, j;
    float iteration = 0.9;

    srand(time(NULL));

    bool matrix[rows][cols];
    bool matrix_next[rows][cols];

    bool n[8];
    int sum_neighbours;

    for (i=0; i < rows; i++) {
        for (j=0; j < cols; j++) {
            matrix[i][j] = ! (rand() & 100);
        }
    }
    
    // main loop
    while(true) {
        printf("1\e[1;1H\e[2J");			
        for (i=0; i < rows; i+=2) {
            for (j=0; j < cols; j++) {
                if (matrix[i][j] && matrix[i+1][j])         printf("█");
                else if (matrix[i][j] && ! matrix[i+1][j])  printf("▀");
                else if (! matrix[i][j] && matrix[i+1][j])  printf("▄");
                else                                        printf(" ");
            }
            printf("\n");
        }
        
        // conways loop
        for (i=0; i < rows; i++) {
            for (j=0; j < cols; j++) {

                sum_neighbours = 0;
                n[0] = matrix[i-1][j-1]; n[1] = matrix[i-1][j]; 
                n[2] = matrix[i-1][j+1]; n[3] = matrix[i][j+1];
                n[4] = matrix[i][j-1];   n[5] = matrix[i+1][j+1];
                n[6] = matrix[i+1][j];   n[7] = matrix[i+1][j-1];
                if (i == 0) { n[0] = n[1] = n[2] = false; }
                if (i == (rows-1)) { n[5] = n[6] = n[7] = false; }
                if (j == 0) { n[0] = n[4] = n[7] = false; }
                if (j == (cols-1)) { n[2] = n[3] = n[5] = false; }
                
                for (int k=0; k<8; k++) {
                    if (n[k]) { sum_neighbours++; }
                }

                if (matrix[i][j]) {
                    matrix_next[i][j] = ! (sum_neighbours < 2 || sum_neighbours > 3) ;
                }
                else {
                    matrix_next[i][j] = (sum_neighbours == 3);
                }
            }
        }
        memcpy(matrix,matrix_next,sizeof(bool)*cols*rows);

        usleep(100000);
    }
}