Regular Bracket Sequence# time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output A string is called bracket sequence if it does not contain any characters other than “(” and “)”. A bracket sequence is called regular if it is possible...
题目链接:http://codeforces.com/problemset/problem/5/C 题目大意: 给出一串字符串只有'('和')',求出符合括号匹配规则的最大字串长度及该长度的字串出现的次数。 解题思路: 设dp[i]为到i的最大括号匹配, 我们每次遇到一个'('就将其下标存入栈中,每次遇到')'就取出当前栈中里它最近的'('下标即栈顶t...
One day Johnny got bracket sequence. He decided to remove some of the brackets from it in order to obtain a regular bracket sequence. What is the maximum length of a regular bracket sequence which can be obtained? Input consists of a single line with non-empty string of «(» and ...
In this blog(https://codeforces.com/blog/entry/87585) you can find number of bracket sequences with lenght 2n with a prefix on k open brackets. I belive(if i didnt missunderstand)your problem reduces to the number with a prefix of k minus the number with a prefix of k+1.(The first...
codeforces 5C 题目大意: 给出一个括号的序列,求最长的合法的子序列。 题目分析: 定义dp[i]表示第i个位置的右括号结尾的合法序列的左边界 定义lef[i]表示第i个位置的右括号匹配到的左括号的位置 利用栈进行模拟,可以得到lef[i],dp[i]的转移方程如下: dp[i]=dp[lef[i]−1](s[lef[i]−1]==′)...
You can replace any bracket by another of the same type. For example, you can replace < by the bracket {, but you can't replace it by ) or >. The following definition of a regular bracket sequence is well-known, so you can be familiar with it. Let's define a regular bracket ...
Can someone help please? How can we efficiently count the number of regular bracket sequences with length 2n2n that have first closing bracket on position k+1k+1 (any way faster than O(nk)O(nk) or O(n2))O(n2))?Compare Revisions History ...
栈Codeforces612C Replace To Make Regular Bracket Sequence,种括号,但是不允许改变括号的开口方向。问最少的操作次数能把括号全部配对思路:运用栈去操作,如果是左括号,则压入栈,如果是右括号,看是否和栈顶配对,如果不配对就ans++,无论是否配对成功都弹出栈顶。
Breadcrumbs CodeForces / 1469A-RegularBracketSequence.cpp Latest commit DionysiosB Create 1469A-RegularBracketSequence.cpp 0ce310c· Dec 29, 2020 HistoryHistory File metadata and controls Code Blame 12 lines (8 loc) · 211 Bytes Raw #include <iostream> int main(){ long t; std::cin >> t;...
12 changes: 12 additions & 0 deletions 12 1132A-RegularBracketSequence.cpp Original file line numberDiff line numberDiff line change @@ -0,0 +1,12 @@ #include <cstdio> int main(){ long a, b, c, d; scanf("%ld %ld %ld %ld", &a, &b, &c, &d); int ans(1); if(a != ...