P2532 [AHOI2012] Treehouse Staircase

 

A positive integer $N$, representing the height of the staircase.

A positive integer, representing the number of ways to build it. **Note**: The number of ways may be very large.

- For $40\%$ of the testdata, $1 \le N \le 20$. - For $80\%$ of the testdata, $1 \le N \le 300$. - For $100\%$ of the testdata, $1 \le N \le 500$. Translated by ChatGPT 5