ASCII star of n using only write sys call (my_putchar)

star.c

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

void my_putchar(char c)
{
    write(1, &c, 1);
}

static void top(unsigned int size) {
    for (int i = size - 1; i >= 0; i--) {
        for (int j = 0; j < size*2; j++) {
            my_putchar(' ');
        }
        for (int j = 0; j < i; j++) {
            my_putchar(' ');
        }
        my_putchar('*');
        if (i != size - 1)
        {
            for (int j = 0; j < 2 * size - 2 * i - 3; j++) {
                my_putchar(' ');
            }
            my_putchar('*');
        }
        my_putchar('\n');
    }
}

static void plateau(unsigned int size) {
    for (int i = 0; i < size * 2 + 1; i++) {
        my_putchar('*');
    }
    for (int i = 0; i < 2 * size - 3; i++) {
        my_putchar(' ');
    }
    for (int i = 0; i < size * 2 + 1; i++) {
        my_putchar('*');
    }
    my_putchar('\n');
}

static void middle(unsigned int size) {
    int space_count = 0;
    int max_lenght = 6 * size - 1;
    for (int i = 0; i < size * 2 - 1; i++)
    {
        if (i <= size - 1)
        {
            space_count++;
        }
        else
        {
            space_count--;
        }
        for (int j = 0; j < space_count; j++)
        {
            my_putchar(' ');
        }
        my_putchar('*');
        for (int j = 0; j < max_lenght - space_count * 2 - 2; j++)
        {
            my_putchar(' ');
        }
        my_putchar('*');
        my_putchar('\n');
    }
}

static void bottom(unsigned int size) {
    for (int i = 0 ; i < size; i++) {
        for (int j = 0; j < size*2; j++) {
            my_putchar(' ');
        }
        for (int j = 0; j < i; j++) {
            my_putchar(' ');
        }
        my_putchar('*');
        if (i != size - 1)
        {
            for (int j = 0; j < 2 * size - 2 * i - 3; j++) {
                my_putchar(' ');
            }
            my_putchar('*');
        }
        my_putchar('\n');
    }
}

static void star_one() {
    // TOP
        for (int i = 0; i < 3; i++) {
            my_putchar(' ');
        }
        my_putchar('*');
        my_putchar('\n');

        // PLATEAU
        for (int i = 0; i < 3; i++) {
            my_putchar('*');
        }
        my_putchar(' ');
        for (int i = 0; i < 3; i++) {
            my_putchar('*');
        }
        my_putchar('\n');

        // MIDDLE
        my_putchar(' ');
        my_putchar('*');
        for (int i = 0; i < 3; i++) {
            my_putchar(' ');
        }
        my_putchar('*');
        my_putchar('\n');

        // PLATEAU
        for (int i = 0; i < 3; i++) {
            my_putchar('*');
        }
        my_putchar(' ');
        for (int i = 0; i < 3; i++) {
            my_putchar('*');
        }
        my_putchar('\n');

        // BOTTOM
        for (int i = 0; i < 3; i++) {
            my_putchar(' ');
        }
        my_putchar('*');
        my_putchar('\n');
}

void star(unsigned int size) {
    if (size == 0) {
        return;
    }
    else if (size == 1)
    {
        star_one();
        return;
    }
    

    top(size);
    plateau(size);
    middle(size);
    plateau(size);
    bottom(size);
}

int main(int argc, char *argv[]) {
    if (argc != 2) {
        printf("Usage: %s <size>\n", argv[0]);
        return 1;
    }

    int size = atoi(argv[1]);

    star(size);

    return 0;
}