hdu 5793 A Boring Question 数学
2016-08-05 10:43
423 查看
思路
∑0≤k1,k2,k3,⋯km≤n∏1≤j<mC(kj+1,kj)=∑km=0nC(n,km)∑km−1=0kmC(km,km−1)⋯∑k1=0k2C(k2,k1)
=∑km=0nC(n,km)∑km−1=0kmC(km,km−1)⋯∑k2=0k3C(k3,k2)×2k2
=∑km=0nmkm
=mn+1−1m−1
没有想到吧k序列反向求和,找不到合适的公式。
相关文章推荐
- hdu 5793 A Boring Question 数学
- HDU - 5793 A Boring Question 数学(打表找规律)
- hdu 5793 A Boring Question (数学 + 快速幂 + 乘法逆元)
- HDU 5793 A Boring Question (数学)
- 16 多校 6 - A - A Boring Question (HDU - 5793)
- HDU 5793 A Boring Question (找规律 : 快速幂+乘法逆元)
- HDU 5793 A Boring Question【快速幂+逆元】
- hdu_5793_A Boring Question(打表找规律)
- hdu 5793 A Boring Question(2016第六场多校)
- 【HDOJ5793】A Boring Question(数学题)
- HDU 5793 A Boring Question
- (HDU 5793)2016 Multi-University Training Contest 6 A Boring Question (规律)
- HDOJ 5793 A Boring Question(快速幂+逆元+数学推导)
- HDU-5793-A Boring Question-打表找规律加模逆元
- HDU 5793 A Boring Question(逆元+快速幂)
- HDOJ 5793 A Boring Question 数学+猜想
- hdu 5793 A Boring Question(2016 Multi-University Training Contest 6——快速幂取模)
- 【HDU】5793 A Boring Question
- HDU 5793 A Boring Question
- hdu-5793 A Boring Question 打表找规律