杨辉三角形

#include<stdio.h>
#include<stdlib.h>
int main(void)
{
    int i, j, a[999] = { 0,1 }, n = 0, x, y;
    while (n < 1 || n>999)
    {
        printf("请输入杨辉三角形的行数:");
        scanf_s("%d", &n);
    }
    for (i = 1; i <= n; i++)
    {
        x = 0;
        for (j = 1; j <= i; j++)
        {
            y = a[j];
            a[j] = x + y;
            x = y;
            printf("%d", a[j]);
        }
        printf("\n");
    }
    system("pause");
    return 0;
}