Description

Print the first $n$ ($2 \leq n \leq 20$) rows of Yang Hui's Triangle (Pascal's Triangle). Yang Hui's Triangle is shown as follows:

When $n=5$

        1
      1   1
    1   2   1
  1   3   3   1
1   4   6   4   1

output:

1
1 1
1 2 1
1 3 3 1
1 4 6 4 1

Input Format

The number of lines $n$.

Output Format

Output the triangle as described. There are $n$ lines, with numbers separated by a single space in each line.

5

1
1 1
1 2 1
1 3 3 1
1 4 6 4 1

来源

CodesOnline