zxa and xor 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=5683 Description zxa had a great interest in exclusive disjunction(i.e. XOR) recently, therefore he took out a non-negative integer sequence a1,a2,⋯,an of length n. zxa thought only doing th…

zxa and xor Time Limit: 16000/8000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Problem Description zxa had a great interest in exclusive disjunction(i.e. XOR) recently, therefore he took out a non-negative integer sequence a1,a2,⋯,a…

题目链接: zxa and xor Time Limit: 16000/8000 MS (Java/Others)     Memory Limit: 65536/65536 K (Java/Others) Problem Description   zxa had a great interest in exclusive disjunction(i.e. XOR) recently, therefore he took out a non-negative integer sequence …

UVA.12716 GCD XOR (暴力枚举 数论GCD) 题意分析 题意比较简单,求[1,n]范围内的整数队a,b(a<=b)的个数,使得 gcd(a,b) = a XOR b. 前置技能 XOR的性质 GCD 由于题目只给出一个n,我们要求对数,能做的也始终暴力枚举a,b,这样就有n^2的复杂度,由于n很大,根本过不了. 于是我们就想用到其中一些性质,如XOR 与GCD,不妨假设 a xor b = c,并且根据题意还知道, gcd(a,b) = c,也就说明c一定是a的因子,所以在枚举的…

其实和昨天写的那道水题是一样的,注意爆LL $1<=n,k<=1e9$,$\sum\limits_{i=1}^{n}(k \mod i) = nk - \sum\limits_{i=1}^{min(n,k)}\lfloor\frac{k}{i}\rfloor i$ /** @Date : 2017-09-21 19:55:31 * @FileName: HDU 2620 分块底数优化 暴力.cpp * @Platform: Windows * @Author : Lweleth (SoungE…

http://acm.hdu.edu.cn/showproblem.php?pid=4712 Hamming Distance Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 797    Accepted Submission(s): 284 Problem Description (From wikipedia) For binary…

YJC counts stars Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5277 Description YJC是个老火车小司机.一个晚上,他仰望天空,星辰璀璨,他突然觉得,天空就像一个平面,而每一个星辰,就是平面中的一个点.他把这些点编号为1到n.这些点满足任意三点不共线.他把一些点用线段连起来了,但是任意两条线段不会在端点以外相交.如果一个点的集合中任意两个…

Teacher Bo 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5762 Description Teacher BoBo is a geography teacher in the school.One day in his class,he marked N points in the map,the i-th point is at (Xi,Yi).He wonders,whether there is a tetrad (A,B,C,…

题目链接:hdu 4876 ZCC loves cards 题目大意:给出n,k,l,表示有n张牌,每张牌有值.选取当中k张排列成圈,然后在该圈上进行游戏,每次选取m(1≤m≤k)张连续的牌,取牌上值的亦或和.要求找到一个圈,使得L~R之间的数都能够得到,输出R.假设R < L输出0. 解题思路:暴力,首先预处理出来每种选取的亦或值,然后在该基础上从能够组成L的状态中挑选一个,L+1的状态中挑取一个,知道说总的挑取出全部状态中选中的牌的个数大于K为值,然后用全排序去查找最大的R. #includ…

http://acm.hdu.edu.cn/showproblem.php?pid=5442 题意:给出一串字符串,它是循环的,现在要选定一个起点,使得该字符串字典序最大(顺时针和逆时针均可),如果有多个字典序相同的,则输出下标最小的,如果下标也是相同的,则输出顺时针方向的. 思路:用了三种方法: ①最简单的,暴力枚举所有情况,需要优化一下,先处理出字符串中字典序最大的单词,然后接下来的起点肯定是这个单词,否则就可以跳过这个起点. #include<iostream> #include<…