在屏幕上用“*”输出指定行数的菱形图案

#define OPP(x) ((x)>0?(x):-(x))int main(){    int n = 0;    int i = 0;    int j = 0;    scanf("%d", &n);    for (i = -n; i <= n; i++)    {        for (j = 1; j <= OPP(i); j++)        {            printf(" ");        }        for (j = 1; j <= 2 * n + 1 - 2 * OPP(i); j++)        {            printf("*");        }        printf("\n");    }    system("pause");    return 0;}