输出n阶倒三角

#include<stdio.h>
int main()
{
	int n;
	while (1)
	{
		scanf("%d", &n);
		if (n > 20 || n <= 0)
			break;
		int i, j, k;
		for (i = n; i > 0; i--)
		{
			for (j = n - i; j > 0; j--)
				printf(" ");
			for (k = 2 * i - 1; k > 0; k--)
				printf("*");
			printf("\n");
		}
	}
	return 0;
}