Kotak dalam kotak (Rekursif)

// Pendekatan Rekursif
#include <stdio.h>

void print_baris(int d, int n, char* c)
{
    int j;

    if (n==1)
        printf(c);
    else {
        n -= 2;

        printf("*");
        if (d==0)
        {
            for (j=0; j<n; j++)
                printf(c);
        } else {
            printf(" ");
            print_baris(d-1, n-2, c);
            printf(" ");
        }
        printf("*");
    }
}

int main()
{
    int n, i, d, m;

    do {
        printf("Size: "); scanf("%d", &n);
    } while (i%2 ==0);

    m = n/2;
    d = 0;
    for (i=0; i<n; i++)
    {
        if (i%2)
        {
            print_baris(d, n, " ");
            if (i<m)
                d++;
        } else {
            print_baris(d, n, "*");
            if (i>=m)
                d--;
        }

        printf("\n");
    }
}