CF1239B The World Is Just a Programming Task 题目描述 定义一个括号序列s是优秀的,当且仅当它是以下几种情况的一种: 1.|s|=0 2.s='('+t+')',其中t是优秀的 3.s=t1+t2,其中t1.t2都是优秀的 一个括号序列的价值为将它看成一个循环串,从多少个位置切开,能切出循环串. 给出一个长度为\(n\)的括号序列,你可以交换其中两个位置的括号(这两个位置可以相等),问最大价值及方案. 输出任意一种方案均正确.\(n\leq 3\tim…

D2. The World Is Just a Programming Task (Hard Version) This is a harder version of the problem. In this version,…

题意: 给你一个长度为n的括号序列,你可以交换其中的两个元素,需要使该序列的n个循环移位中合法的括号序列个数尽量多. 输出最大的答案以及交换哪两个元素能够取到这个答案. $n\leq 3\times 10^5$. 题解: 这位julao讲得很清楚. 这个题值得学习的地方就是把括号序列转化成平面直角坐标系上的折线再进行判断. 将右括号视作-1,左括号视作+1,$sum_{i}$为$1-i$的前缀和,那么一个括号序列合法当且仅当: 1.不存在$i$满足$sum_{i}<0$: 2.$sum_{n}=…

传送门 这一题好妙啊 首先把括号序列转化成平面直角坐标系 $xOy$ 上的折线,初始时折线从坐标系原点 $(0,0)$ 出发 如果第 $i$ 个位置是 '(' 那么折线就往上走一步($y+1$),否则往下走一步 ($y-1$) 这条折线有很多有用的性质 $1.$如果某个时刻折线的纵坐标为负数了,那么说明这个括号序列一定是不合法的 证明也挺好理解的,变成负数说明没有足够的 '(' 和 ')' 匹配了,显然不合法 $2.$如果最终位置 $n$ 的折线 $y$ 坐标不为 $0$ ,那么一定不合法,因为…

题目链接: http://codeforces.com/contest/1248/problem/D2 题意: 可以执行一次字符交换的操作 使得操作后的字符串,循环移位并且成功匹配的方案最多 输出最多的方案数和交换的位置 数据范围: $1\leq n \leq 300 000$ 分析: 参考博客:https://www.cnblogs.com/LLTYYC/p/11718968.html 对于一个字符串,求它的循环移位匹配方案数 可以把字符串转换成折线,从0开始,遇到(则加一,遇到)则减一 如果…

题目传送门 题意: 给定一个括号序列,随意交换两个位置的括号之后,问有多少个不同长度的圈.关于圈的定义大概就是:将括号序列的后$k$个数放到括号序列的最前面,就是长度为$k$的圈.(看了好久题意emmm...) 分析: 首先,我们可以$n^2$暴力枚举交换的位置,然后再看有多少个圈. 然后,对于括号序列的正确性判断,有一个非常巧妙的方法,(只适用于只有一种括号,既有小括号,又有中括号是不得行的): 给$"("$赋值为1,$")"$赋值为-1,计算这个序列的前缀和,只…

思路:枚举换的位置i,j 然后我们要先判断改序列能否完全匹配 如果可以 那我们就需要把差值最大的位置换过来 然后直接判断就行…

思路:枚举换的位置i,j 然后我们要先判断改序列能否完全匹配 如果可以 那我们就需要把差值最大的位置换过来 然后直接判断就行…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 27539   Accepted: 9290 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…

"I worked up a full implementation as well but I decided that it was too complicated to post in the blog. What I was really trying to get across was that immutable data structures were possible and not that hard; a full-on finger tree implementation…

Musical Theme   Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the piano. It is unfortunate but true that this representation of melodies ignores the…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 25348   Accepted: 8546 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…

POJ   1743 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the piano. It is unfortunate but true that this representation of melodies ignores the noti…

Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the piano. It is unfortunate but true that this representation of melodies ignores the notion of music…

永恒的大牛,kuangbin,膜拜一下,Orz 链接:http://www.cnblogs.com/kuangbin/archive/2013/04/23/3039313.html Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 14334   Accepted: 4945 Description A musical melody is represented as a sequence of…

Large Scale Visual Recognition Challenge 2015 (ILSVRC2015) Legend: Yellow background = winner in this task according to this metric; authors are willing to reveal the method White background = authors are willing to reveal the method Grey background…

Musical ThemeTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://poj.org/problem?id=1743 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the piano. It…

Musical Theme Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the piano. It is unfortunate but true that this representation of melodies ignores the n…

2015-08-25   008   Foreword    QUOTE: I think that it's extraordinarily important that we in computer science keep fun in computing...... What's in your hands, I think and hope, is intelligence: the ability to see the machine as more than when you we…

2015-03-06   328   Unusual Data Types    ——You can carry this technique to extremes,putting all the variables in your program into one big,juicy variable and then passingit everywhere.Careful programmers avoid bundling data any more than is logically…

直接枚举O(n^3)会TLE,只要稍微加点优化,在不可能得到更优解时及时退出.其实就是道水题,虽说我提交了6次才过= =..我还太弱了 -------------------------------------------------------------------------- #include<cstdio> #include<iostream> #include<cstring> #include<algorithm> #include<cc…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 14874   Accepted: 5118 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…

Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the piano. It is unfortunate but true that this representation of melodies ignores the notion of music…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 16757   Accepted: 5739 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 24835   Accepted: 8377 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…

In this post I explain how to compute PageRank using the MapReduce approach to parallelization. This gives us a way of computing PageRank that can in principle be automatically parallelized, and so potentially scaled up to very large link graphs, i.e…

Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 33462   Accepted: 11124 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the piano. It is…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 33820   Accepted: 11259 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 27539   Accepted: 9290 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…

Musical Theme Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 15900   Accepted: 5494 Description A musical melody is represented as a sequence of N (1<=N<=20000)notes that are integers in the range 1..88, each representing a key on the…