A Boring Question Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 865    Accepted Submission(s): 534 Problem Description There are an equation.∑0≤k1,k2,⋯km≤n∏1⩽j<m(kj+1kj)%1000000007=?We define…

A Boring Question 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5793 Description Input The first line of the input contains the only integer T, Then T lines follow,the i-th line contains two integers n,m. Output For each n and m,output the answer i…

传送门 zhx's contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 575    Accepted Submission(s): 181 Problem Description As one of the most powerful brushes, zhx is required to give his juniors…

HDU 5793 - A Boring Question题意: 计算 ( ∑(0≤K1,K2...Km≤n )∏(1≤j<m) C[Kj, Kj+1]  ) % 1000000007=? (C[Kj, Kj+1] 为组合数)    分析: 利用二项式展开: (a + b) ^ n =  ∑(r = 0, n) (C[n, r] * a^(n-r) * b^r )        化简:           ∑(0≤K1,K2...Km≤n )∏(1≤j<m) C[Kj, Kj+1]       …

参考博客:http://www.cnblogs.com/Sunshine-tcf/p/5737627.html. 说实话,官方博客的推导公式看不懂...只能按照别人一样打表找规律了...但是打表以后其实也不是很好看出规律的...而且这个表都写了半天233...(真是太弱了= =)为了打表,我们应当先知道k数列必须是不递减的才能满足值不为0,因此我们可以用递归来写这个表(类似于dfs). AC代码如下: #include <stdio.h> #include <algorithm>…

A Boring Question Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 156    Accepted Submission(s): 72 Problem Description       Input   The first line of the input contains the only integer T,(1≤T…

A Boring Question Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 487    Accepted Submission(s): 271 Problem Description There are an equation.∑0≤k1,k2,⋯km≤n∏1⩽j<m(kj+1kj)%1000000007=? We define…

There are an equation. ∑0≤k1,k2,⋯km≤n∏1⩽j<m(kj+1kj)%1000000007=?∑0≤k1,k2,⋯km≤n∏1⩽j<m(kj+1kj)%1000000007=? We define that (kj+1kj)=kj+1!kj!(kj+1−kj)!(kj+1kj)=kj+1!kj!(kj+1−kj)! . And (kj+1kj)=0(kj+1kj)=0 while kj+1<kjkj+1<kj. You have to get th…

题目链接:https://nanti.jisuanke.com/t/31716 题目大意:有n个孩子和n个糖果,现在让n个孩子排成一列,一个一个发糖果,每个孩子随机挑选x个糖果给他,x>=1,直到无糖果剩余为止.给出数字n,问有多少种分发糖果的方法. 样例输入 复制 1 4 样例输出 复制 8 解题思路:我们可以这样想,一个糖果的话,应该是只有1种方法记为x1,如果是两个糖果的话,有两种方法即为x2,分别为(1,1)和(2),从中我们可以想到如果n个糖果的话,就可以分为第n个人取1个的话就有x(…

链接:https://ac.nowcoder.com/acm/contest/153/1047 来源:牛客网 题目描述 给定一个正整数k( ≤ k ≤ ),把所有k的方幂及所有有限个互不相等的k的方幂之和构成一个递增的序列,例如,当k = 3时,这个序列是: ,,,,,,,…(该序列实际上就是:,,+,,+,+,++,…) 请你求出这个序列的第N项的值(用10进制数表示).例如,对于k = ,N = ,正确答案应该是 . 输入描述: 输入1行,为2个正整数,用一个空格隔开:k N(k.N的含义与…