>>94 あまり悩まずに回答
char pat[][4][3]={{"□","☆","□","□"},
{"☆","★","☆","☆"},{"□","☆","□","□"}};
main()
{int x, y, i, j;
scanf("%d%d", &x, &y);
for (i = 0; i < x; i++) {
for (j = 0; j < y; j++)
printf("%s", pat[i%3][j%4]);
printf("\n"); }
return 0;
}