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

int main()
{
    int a[9][9] = { 0 };
    int i, j, k;
    srand(time(NULL));

    printf("|-------------------|\n");

    for (i = 0; i < 9; i++)
    {
        for (j = 0; j < 9; j++)
        {
            if (j % 3 == 0)
                printf("|");

            if (rand() % 3 == 0)
            {
                do
                {
                    k = rand() % 9 + 1;
                } while (a[i][k - 1] != 0);

                a[i][k - 1] = k;
                printf("%d", k);
            }
            else
            {
                a[i][j] = 0;
                printf(".");
            }

            if (j == 8)
                printf("|");

            printf(" ");
        }

        printf("\n");

        if ((i + 1) % 3 == 0)
            printf("|-------------------|\n");
    }

    return 0;
}