LINK 题意:给出n个[l,r],q个询问a,b,问被包含于[a,b]且这样的区间数大于k个的方案数有多少 思路:预处理所有的区间,对于一个区间我们标记其(左边界)++,(右边界+1)--这样就能通过前缀和维护小于某边界的区间个数了 这题也可以用线段树解,但显然不太合算 /** @Date : 2017-07-01 10:02:30 * @FileName: 816B 前缀和 线段树 二分.cpp * @Platform: Windows * @Author : Lweleth (SoungE…

CodeForces 816B Karen and Coffee(前缀和,大量查询) Description Karen, a coffee aficionado, wants to know the optimal temperature for brewing the perfect cup of coffee. Indeed, she has spent some time reading several recipe books, including the universally ac…

题目链接 816B Karen and Coffee 题目分析 题意:有个人在学泡咖啡,因此看了很多关于泡咖啡温度的书,得到了n种推荐的泡咖啡温度范围[L1,R1] ,此人将有k种做法推荐的温度记为可用温度(个人翻译),然后给出q次询问,问区间[L2,R2]内的温度,有多少个温度是可用温度(每个整数代表一个温度) 思路:一开始用的是线段树写的,不过姿势不对,TLE了,然后改过来后,发现时间比较长,就考虑一下优化的方法. 比线段树某些功能更优的算法:差分思想,在对某一区间每个位置上的数加上一个值x…

To stay woke and attentive during classes, Karen needs some coffee! Karen, a coffee aficionado, wants to know the optimal temperature for brewing the perfect cup of coffee. Indeed, she has spent some time reading several recipe books, including the u…

https://www.lydsy.com/JudgeOnline/problem.php?id=4627 题意:求序列中和在L到R之间的字串种数. 要求的是和的范围,我们可以考虑先求一个前缀和pre,然后每个点j的贡献就是L <= pre[j] - pre[i] <= R(i < j)的i的种数了,移项一下变成 pre[j] - R <= pre[i] <= pre[j] - L 我们就可以考虑做个权值线段树维护一下所有pre,每次求贡献的时候做一个区间查询就可以了. 注意…

An easy problem Time Limit: 8000/5000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 1327    Accepted Submission(s): 624 Problem Description One day, a useless calculator was being built by Kuros. Let's assume that…

题目链接:http://codeforces.com/contest/816/problem/B 题目意思:给出 n 个recipes,第 i 个(1<= i <=n)recipes 表明 coffee 调制的推荐温度范围是 [li, ri] 之间.现在有 q 个问题,每个问题需要回答 coffee 在范围 [a, b] 之间,共有多少个数满足至少有 k 个推荐. 题目解析:这题主要是考我们对于大范围(最大200000),如何处理数据.方法是很容易想到的,但要考虑优化,即离线处理.20w *…

我这种maintain写法好zz.考试时获得了40pts的RE好成绩 In mathematical terms, the sequence Fn of Fibonacci numbers is defined by the recurrence relation F1 = 1; F2 = 1; Fn = Fn - 1 + Fn - 2 (n > 2). DZY loves Fibonacci numbers very much. Today DZY gives you an array con…

To stay woke and attentive during classes, Karen needs some coffee! Karen, a coffee aficionado, wants to know the optimal temperature for brewing the perfect cup of coffee. Indeed, she has spent some time reading several recipe books, including the u…

Description To stay woke and attentive(专注的) during classes, Karen needs some coffee! Karen, a coffee aficionado, wants to know the optimal temperature for brewing the perfect cup of coffee. Indeed, she has spent some time reading several recipe books…