摘要：组合数学的推式子题公式基本上都有了 \(\Large\sum_{i=0}^nC_n^i=2^n\) \(\Large\sum_{i=0}^nC_n^i(-1)^i=0\) \(\Large\sum_{i=0}^nC_n^ix^i=(1+x)^n\) \(\Large C_n^kC_k^i=C_n^i 阅读全文

摘要：题目链接 题目 There is a n×m board, a chess want to go to the position (n,m) from the position (1,1). The chess is able to go to position (x2,y2) from the p 阅读全文

摘要：Lacus 求： \(\Large C_m^n~mod ~p\) 则： \(\Large C_m^n~mod~p=C_{\frac{m}{p}}^{\frac{n}{p}} \times C_{m~mod~p}^{n~mod~p}~mod~p\) 由于 \(C_{m~mod~p}^{n~mod~p} 阅读全文