#include<stdio.h>
int main()
{
    int i, j, n = 0, a[100][100] = { 1 };
    while (n < 1 || n>99)
    {
        printf("请输入杨辉三角形的行数:");
        scanf_s("%d", &n);
    }
    for (i = 1; i < n; i++)
    {
        a[i][0] = 1;
        for (j = 1; j <= i; j++)
            a[i][j] = a[i - 1][j - 1] + a[i - 1][j];
    }
    for (i = 0; i < n; i++)
    {
        for (j = 0; j <= i; j++)
            printf("%5d", a[i][j]);
        printf("\n");
    }
return 0;
}