题目链接:https://vjudge.net/contest/155789#problem/E 题解: 由于是回文串,所以可以先将在对称位置的字符放在同一个集合(如果期间有两个非‘?’,且不相等,则退出操作.并跳过之后的某些步骤.注意输入不能跳过).然后再接收输入的限制条件,进行并查集.有两种并查集的方式,而两种方式的共同点都是根节点存放这个集合的字符值. 方法一(根据字符的情况选择根节点) 1.如果两个结点的祖先的字符相等,则随便一个结点的祖先做根节点: 2.如果一个的祖先是‘?’,一个的祖…

De Prezer loves palindrome strings. A string s1s2...sn is palindrome if and only if it is equal to its reverse. De Prezer also loves queries. You are given string s of length n and m queries. There are 3 types of queries : 1. 1px : Modify sp = x wher…

E. Palindrome QueryTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100570/problem/E Description De Prezer loves palindrome strings. A string s1s2...sn is palindrome if and only if it is equal to its reverse. De Prezer also love…

H. Special Palindrome time limit per test:1 second memory limit per test:64 megabytes input:standard input output:standard output A sequence of positive and non-zero integers called palindromic if it can be read the same forward and backward, for exa…

C. Palindrome Again !! time limit per test:1 second memory limit per test:64 megabytes input:standard input output:standard output Given string with N characters, your task is to transform it to a palindrome string. It's not as easy as you may think…

http://codeforces.com/gym/100952/problem/H H. Special Palindrome time limit per test 1 second memory limit per test 64 megabytes input standard input output standard output A sequence of positive and non-zero integers called palindromic if it can be…

http://codeforces.com/gym/100952/problem/C C. Palindrome Again !! time limit per test 1 second memory limit per test 64 megabytes input standard input output standard output Given string with N characters, your task is to transform it to a palindrome…

题意:给定字符串char[],以及Q个操作,操作有三种: 1:pos,chr:把pos位置的字符改为chr 2:pos:问以pos为中心的回文串长度为多长. 3:pos:问以pos,pos+1为中心的回文串长度为多长. 思路:用hash表示一段字符串或者连续子串.我们用BIT记录hash前缀和,那么也可以用BIT修改前缀和.然后blabla,乱搞就行了. 当然为了保险,最好用双hash. (此题暴力也可以过! 暴力代码:3962ms #include<bits/stdc++.h> #defin…

题目链接:http://codeforces.com/gym/100971/problem/K K. Palindromization time limit per test 2.0 s memory limit per test 256 MB input standard input output standard output Mihahim has a string s. He wants to delete exactly one character from it so that th…

A positive integer is called a palindrome if its representation in the decimal system is the same when read from left to right and from right to left. For a given positive integer K of not more than 1000000 digits, write the value of the smallest pal…

Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters. This is case sensitive, for example "Aa" is not considered a palindrome here. Note: Assume the leng…

Given a list of unique words. Find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e. words[i] + words[j] is a palindrome. Example 1:Given words = ["bat", "tab", "cat"]Ret…

Given a string s, return all the palindromic permutations (without duplicates) of it. Return an empty list if no palindromic permutation could be form. For example: Given s = "aabb", return ["abba", "baab"]. Given s = "a…

Given a string, determine if a permutation of the string could form a palindrome. For example,"code" -> False, "aab" -> True, "carerac" -> True. Hint: Consider the palindromes of odd vs even length. What difference d…

Given a singly linked list, determine if it is a palindrome. Follow up: Could you do it in O(n) time and O(1) space? 这道题让我们判断一个链表是否为回文链表,LeetCode中关于回文串的题共有六道,除了这道,其他的五道为Palindrome Number 验证回文数字,Validate Palindrome 验证回文字符串,Palindrome Partitioning 拆分回文…

Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrome you can find by performing this transformation. For example: Given "aacecaaa", return "aaacecaaa&qu…

Given a string s, partition s such that every substring of the partition is a palindrome. Return the minimum cuts needed for a palindrome partitioning of s. For example, given s = "aab", Return 1 since the palindrome partitioning ["aa"…

Given a string s, partition s such that every substring of the partition is a palindrome. Return all possible palindrome partitioning of s. For example, given s = "aab",Return [ ["aa","b"], ["a","a","…

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example, "A man, a plan, a canal: Panama" is a palindrome. "race a car" is not a palindrome. Note: Have you consider that…

Determine whether an integer is a palindrome. Do this without extra space. click to show spoilers. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer to string, note the restriction of using ext…

题目简述: Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example, "A man, a plan, a canal: Panama" is a palindrome. "race a car" is not a palindrome. Note: Have you conside…

题目简述: Determine whether an integer is a palindrome. Do this without extra space. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer to string, note the restriction of using extra space. You coul…

参考:http://www.cppblog.com/wicbnu/archive/2013/03/18/198565.html 我太喜欢用dfs和回溯法了,但是这些暴力的方法加上剪枝之后复杂度依然是很高,显然不能达到题目的要求. 这个时候应该考虑动态规划,并且要复杂度尽量接近O(n^2)的算法. 下面这个方法更加简洁:自长到短找到回文串后,往后dfs,并记录递归深度表示并更新最小划分数.http://fisherlei.blogspot.com/2013/03/leetcode-palindro…

Given a singly linked list, determine if it is a palindrome. Follow up:Could you do it in O(n) time and O(1) space? 题目意思: 给定一个单链表,判断它是不是回文串 进一步思考: 你可以在O(n)时间复杂度和O(1)空间复杂度完成吗? 解题思路: 方法一:通过反转链表实现 (1)使用快慢指针寻找链表中点 (2)将链表的后半部分就地逆置 (3)比较前后两半的元素是否一致 (4)恢复原始…

 Gym 101047M Removing coins in Kem Kadrãn Time Limit:2000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Practice Description standard input/output Andréh and his friend Andréas are board-game aficionados. They know many of their friend…

 Gym 101047K Training with Phuket's larvae Time Limit:2000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Practice Description standard input/output Thai cuisine is known for combining seasonings so that every dish has flavors that are…

Gym 101047E Escape from Ayutthaya Time Limit:2000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u  Practice  Description standard input/output Ayutthaya was one of the first kingdoms in Thailand, spanning since its foundation in 1350 to…

 Gym 101047B  Renzo and the palindromic decoration Time Limit:2000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Practice Description standard input/output At the ruins of Wat Phra Si Sanphet (วดพระศรสรรเพชญ), one can find famous inscr…

1. Description Given a list of unique words. Find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e. words[i] + words[j] is a palindrome. Example 1: Given words = ["bat", "tab", &qu…

问题: Determine whether an integer is a palindrome. Do this without extra space. 官方难度: Easy 翻译: 不使用额外空间,判断一个数是不是回文形式. 暂定负数不参与讨论. 先获取数值长度,取得对应位置的数字比较. 重点是如何取到一个整数指定位置的数字,通过(x/Math.pow(10,n-1))%10来实现. 循环至一半就可以退出. 解题代码: public static boolean isPalindrome(…