#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
	int arr[5] = { 0,1,2,3,4 };
	int i = 0;
	for (i = 4; i >= 0; i--)
	{
		printf("%d ", arr[i]);
	}

	system("pause");
	return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
	int i, j, n = 0, a[17][17] = { 0 };

	while (n<1 || n>16)

	{
		printf("请输入杨辉三角形的行数:");

		scanf("%d", &n);

	}

	for (i = 0; i<n; i++)

		a[i][0] = 1; /*第一列全置为一*/

	for (i = 1; i<n; i++)

		for (j = 1; j <= i; j++)

			a[i][j] = a[i - 1][j - 1] + a[i - 1][j];/*每个数是上面两数之和*/


	for (i = 0; i<n; i++) /*输出杨辉三角*/

	{
		for (j = 0; j <= i; j++)

			printf("%5d", a[i][j]);

		printf("\n");

	}
	system("pause");
	return 0;
}