传送门 题意 给出n个数,m次访问,每次询问[L,R]的数有多少种排列 分析 \(n,m<=30000\),我们采用莫队算法,关键在于区间如何\(O(1)\)转移,由排列组合知识得到,如果加入一个数,\(区间值*区间长度/该数出现次数\),减去一个数则相反操作讲解 trick 1.我的原先莫队写法不能ac,原因是我传入的L,R是全局变量,在insert和erase前就++,--了,而没有达到预期目的,把R++,L--分离即可 代码 //wa #include <bits/stdc++.h>…

NPY and girls Problem Description NPY's girlfriend blew him out!His honey doesn't love him any more!However, he has so many girlfriend candidates.Because there are too many girls and for the convenience of management, NPY numbered the girls from 1 to…

Time Limit: 8000/4000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Problem Description NPY's girlfriend blew him out!His honey doesn't love him any more!However, he has so many girlfriend candidates.Because there are too many girls and…

题目连接:http://acm.hdu.edu.cn/showproblem.php?pid=5145 题意:给你n,m,共有n个女孩,标号为1—n,n个数xi表示第ith个女孩在第xi个教室,然后下面有m个询问,每个询问有l,r两个数,表示要去找编号为l到r的女孩,每进一次教室只能找一个女孩,问有多少种组合方式,不同的组合方式定义为去教室的顺序不同. 题解:这题是离线的,很容易想到用莫队分块做,主要是要找出状态转移的方程,对于询问区间[l,r],假设这个区间的女孩一共分布在k个教室,每个教室有…

题意: cases T(1≤T≤10) (0<n,m≤30000) (0<ai≤30000)    n个数ai 表示n个女孩所在教室 m次询问 [L,R](1 <= L <= R <= n)     问访问所有女孩的顺序方案数(进教室顺序)为多少(一次进教室只能访问一个人)    分析: 莫队算法 + 排列数 一个区间内的方案数为 C(m,c1)*C(m-c1,c2)*C(m-c1-c2,c3)*....*C(cn,cn)    每次转移通过下式: C(m+1,n+1) =…

[题目链接] http://acm.hdu.edu.cn/showproblem.php?pid=5145 [题目大意] 给出一个数列,每次求一个区间数字的非重排列数量.答案对1e9+7取模. [题解] 我们发现每次往里加入一个新的数字或者减去一个新的数字,前后的排列数目是可以通过乘除转移的,所以自然想到用莫队算法处理.因为答案要求取模,所以在用除法的时候要计算逆元. [代码] #include <cstdio> #include <algorithm> #include <…

NPY and girls Time Limit: 8000/4000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 790    Accepted Submission(s): 280 Problem Description NPY's girlfriend blew him out!His honey doesn't love him any more!However, he…

Sona Time Limit:5000MS     Memory Limit:65535KB     64bit IO Format: Submit Status Practice NBUT 1457 Appoint description:  Description Sona, Maven of the Strings. Of cause, she can play the zither. Sona can't speak but she can make fancy music. Her…

2038: [2009国家集训队]小Z的袜子(hose) Time Limit: 20 Sec  Memory Limit: 259 MBSubmit: 7687  Solved: 3516[Submit][Status][Discuss] Description 作为一个生活散漫的人,小Z每天早上都要耗费很久从一堆五颜六色的袜子中找出一双来穿.终于有一天,小Z再也无法忍受这恼人的找袜子过程,于是他决定听天由命……具体来说,小Z把这N只袜子从1到N编号,然后从编号L到R(L 尽管小Z并不在意两只…

XOR and Favorite Number time limit per test: 4 seconds memory limit per test: 256 megabytes input: standard input output: standard output Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Each query is given by a pa…