void test2()
{
//打印出这个图形:
/*
*******
*****
***
*
***
*****
*******
*/
for(int row = -3 ;row < 4; row++){
int k = row > 0 ? row : -row;
//打印空格
for (int col = 0; col < 3 - k; col++){
printf(" ");
}
//打印*
for (int i = 0; i < 2 * k + 1;i++){
printf("*");
}
printf("\n");
}
}