A bracket sequence is a string, containing only characters "(", ")", "[" and "]". A correct bracket sequence is a bracket sequence that can be transformed into a correct arithmetic expression by inserting characters…

ACM思维题训练集合 A bracket sequence is a string, containing only characters "(", ")", "[" and "]". A correct bracket sequence is a bracket sequence that can be transformed into a correct arithmetic expression by inserting…

C. Replace To Make Regular Bracket Sequence 题目连接: http://www.codeforces.com/contest/612/problem/C Description You are given string s consists of opening and closing brackets of four kinds <>, {}, [], (). There are two types of brackets: opening and…

C. Longest Regular Bracket Sequence Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/problem/5/C Description This is yet another problem dealing with regular bracket sequences. We should remind you that a bracket sequence…

题意:给你一串括号,每次仅可以修改一个位置,问有多少位置仅修改一次后所有括号合法. 题解:我们用栈来将这串括号进行匹配,每成功匹配一对就将它们消去,因为题目要求仅修改一处使得所有括号合法,所以栈中最后一定会有两个括号剩余,并且这两个括号要么是\(((\)要么是\())\),\()(\)是无论如何都不合法的,对于\())\),我们去找它左边的\()\)的个数贡献给答案(因为每次修改可以使[\((++\),\()--\)],所以栈中剩余的\())\)就没有了),对于\(((\)的情况也是一样的,我们…

题目链接: http://codeforces.com/contest/670/problem/E 题解: 用STL的list和stack模拟的,没想到跑的还挺快. 代码: #include<iostream> #include<cstdio> #include<cstring> #include<map> #include<list> #include<stack> using namespace std; + ; const in…

(CodeForces - 5C)Longest Regular Bracket Sequence time limit per test:2 seconds memory limit per test:256 megabytes input:standard input output:standard output This is yet another problem dealing with regular bracket sequences. We should remind you t…

E. Correct Bracket Sequence Editor 题目连接: http://www.codeforces.com/contest/670/problem/E Description Recently Polycarp started to develop a text editor that works only with correct bracket sequences (abbreviated as CBS). Note that a bracket sequence…

E. Correct Bracket Sequence Editor time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Recently Polycarp started to develop a text editor that works only with correct bracket sequences (abbrev…

C. Replace To Make Regular Bracket Sequence time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given string s consists of opening and closing brackets of four kinds <>, {}, [], (). Th…