As we know, Rikka is poor at math. Yuta is worrying about this situation, so he gives Rikka some math tasks to practice. There is one of them: Correct parentheses sequences can be defined recursively as follows: 1.The empty string "" is a correc…

31 Rikka with Parenthesis II (六花与括号II) Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Description 题目描述 As we know, Rikka is poor at math. Yuta is worrying about this situation, so he gives Rikka some math tasks to…

Rikka with Parenthesis II 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5831 Description As we know, Rikka is poor at math. Yuta is worrying about this situation, so he gives Rikka some math tasks to practice. There is one of them: Correct parenthe…

Rikka with Parenthesis II 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=5831 Description As we know, Rikka is poor at math. Yuta is worrying about this situation, so he gives Rikka some math tasks to practice. There is one of them: Correct parenthe…

Rikka with Parenthesis II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 0    Accepted Submission(s): 0 Problem Description As we know, Rikka is poor at math. Yuta is worrying about this situat…

Rikka with Parenthesis II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 136    Accepted Submission(s): 97 Problem Description As we know, Rikka is poor at math. Yuta is worrying about this sit…

题目:传送门. 题意:T组数据,每组给定一个长度n,随后给定一个长度为n的字符串,字符串只包含'('或')',随后交换其中两个位置,必须交换一次也只能交换一次,问能否构成一个合法的括号匹配,就是()()或者((()))这种的. 题解:首先n为奇数肯定是No,左括号和右括号个数不相等是No,n=2的时候如果是()也是no,因为必须交换一次,就会变成)(,所以是No.否则如果出现一个没有与其相匹配的右括号,就是右括号出现在与他匹配的左括号之前,如果这种情况出现了三次或三次以上就是No,其余是Yes.…

BUPT2017 wintertraining(16) #4 G HDU - 5831 题意 给定括号序列,问能否交换一对括号使得括号合法. 题解 注意()是No的情况. 任意时刻)不能比(超过2个以上. 最后)和(的差距要在两个以内,且n必须是偶数. 代码 #include <cstdio> #include <cstring> #include <algorithm> #include <iostream> using namespace std; ch…

如果左括号数量和右括号数量不等,输出No 进行一次匹配,看匹配完之后栈中还有多少元素: 如果n=2,并且栈中无元素,说明是()的情况,输出No 如果n=2,并且栈中有元素,说明是)(的情况,输出Yes 如果n>2,并且栈中没有元素,或者有2个,或者有4个,输出Yes 如果n>2,并且栈中元素个数大于4个,输出No #pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #i…

用一个temp变量,每次出现左括号,+1,右括号,-1:用ans来记录出现的最小的值,很显然最终temp不等于0或者ans比-2小都是不可以的.-2是可以的,因为:“))((”可以把最左边的和最右边的交换即可,其他-2的情形同理.另外要注意的坑点是Hint里面所说的:“But do nothing is not allowed.”.因此,“()”是不可以的,这个要特判. 代码如下: #include <stdio.h> #include <algorithm> #include &…