Problem Description CRB has N different candies. He is going to eat K candies. He wonders how many combinations he can select. Can you answer his question for all K(0 ≤ K ≤ N)? CRB is too hungry to check all of your answers one by one, so he only ask…

CRB and Candies Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 722    Accepted Submission(s): 361 Problem Description CRB has N different candies. He is going to eat K candies.He wonders how ma…

题意: 输入n,求c(n,0)到c(n,n)的所有组合数的最小公倍数. 输入: 首行输入整数t,表示共有t组测试样例. 每组测试样例包含一个正整数n(1<=n<=1e6). 输出: 输出结果(mod 1e9+7). 感觉蛮变态的,从比赛开始我就是写的这道题,比赛结束还是没写出来…… 期间找到了逆元,最小公倍数,组合数的各种公式,但是爆了一下午tle. 比赛结束,题解告诉我,公式秒杀法…… 但是公式看不懂,幸好有群巨解说,所以有些听懂了,但还是需要继续思考才能弄懂. 题解: 设ans[i]表示i…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5407 题目: Problem Description CRB has N different candies. He is going to eat K candies.He wonders how many combinations he can select.Can you answer his question for all K(0 ≤ K ≤ N)?CRB is too hungry to…

题目地址:pid=5407">HDU 5407 题意:CRB有n颗不同的糖果,如今他要吃掉k颗(0<=k<=n),问k取0~n的方案数的最小公倍数是多少. 思路:首先做这道题我们须要必备的几个技能点. 1. LCM(C(n,0), C(n,1),-, C(n,n))=LCM(1,2,3,-n+1)/(n+1).额,这个有一篇证明Kummer定理 2.(1) 乘法逆元定义: 满足a*k≡1 (mod p)的k值就是a关于p的乘法逆元(a,p互质). (2)为什么要用乘法逆元: 当…

[题目链接]pid=5407">click here~~ [题目大意]求LCM(Cn0,Cn1,Cn2....Cnn)%MOD 的值 [思路]来图更直观: 这个究竟是怎样推出的.说实话.本人数学归纳大法没有推出来,幸得一个大神给定愿文具体证明.点击这里:click here~~ 代码: #include <bits/stdc++.h> using namespace std; const int N=1e6+10; const int MOD=1e9+7; typedef lo…

xiaoxin juju needs help 题意:给你一个字符串,求打乱字符后,有多少种回文串.                      (题于文末) 知识点: n个元素,其中a1,a2,····,an互不相同,进行全排列,可得n!个不同的排列. 若其中某一元素ai重复了ni次,全排列出来必有重复元素,其中真正不同的排列数应为 ,即其重复度为ni! 同理a1重复了n1次,a2重复了n2次,····,ak重复了nk次,n1+n2+····+nk=n. 对于这样的n个元素进行全排列,可得不同排…

<题目链接> <转载于 >>> > Problem Description CRB has N different candies. He is going to eat K candies.He wonders how many combinations he can select.Can you answer his question for all K(0 ≤ K ≤ N)?CRB is too hungry to check all of your ans…

Problem Description Function Fx,ysatisfies:For given integers N and M,calculate Fm,1 modulo 1e9+7.   Input There is one integer T in the first line.The next T lines,each line includes two integers N and M .1<=T<=10000,1<=N,M<2^63.   Output For…

xiaoxin juju needs help Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 1159    Accepted Submission(s): 335 Problem Description As we all known, xiaoxin is a brilliant coder. He knew **palindrom…