Palindromic Subsequence Time Limit:3000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu Submit Status Practice UVA 11404 #include <stdio.h> #include <string.h> #include <algorithm> #include <string> #include <iostrea…

UVA 11404 我用了最暴力的做法:考虑\(dp[i][j]\)表示\(S[i..j]\)的最长回文子序列的长度以及字典序最小的那个. 然后转移的时候如下处理:首先\(dp[i][j]\)要取\(dp[i+1][j]\)和\(dp[i][j-1]\)的最大值(因为可以两端中有一个不取), 然后如果\(S[i]=S[j]\),那么我们就可以从\(dp[i+1][j-1]+2\)转移过来,并且字符串也需要更新. 然后比较字典序的时候就直接暴力按位比较. 最后只要注意一下多测把所有dp值都要赋初值…

UVA - 11404 Palindromic Subsequence 题意:一个字符串,删去0个或多个字符,输出字典序最小且最长的回文字符串 不要求路径区间DP都可以做 然而要字典序最小 倒过来求LCS,转移同时维护f[i][j].s为当前状态字典序最小最优解 f[n][n].s的前半部分一定是回文串的前半部分(想想就行了) 当s的长度为奇时要多输出一个(因为这样长度+1,并且字典序保证最小(如axyzb  bzyxa,就是axb|||不全是回文串的原因是后半部分的字典序回文串可能不是最小,多…

题目传送门 题意:求LPS (Longest Palidromic Subsequence) 最长回文子序列.和回文串不同,子序列是可以不连续的. 分析:1. 推荐->还有一种写法是用了LCS的思想,dp[i][j]表示i到j的最长回文串长度,状态转移方程: 1. dp[j][j+i-1] = dp[j+1][j+i-2] + 2; (str[j] == str[j+i-1]) 2. dp[j][j+i-1] = max (dp[j+1][j+i-1], dp[j][j+i-2]); (str[…

Palindromic Subsequence Time Limit: 3000ms Memory Limit: 131072KB This problem will be judged on UVA. Original ID: 1140464-bit integer IO format: %lld      Java class name: Main   A Subsequence is a sequence obtained by deleting zero or more characte…

UVA 11404 - Palindromic Subsequence 求给定字符串的最长回文子序列,长度一样的输出字典序最小的. 对于 [l, r] 区间的最长回文串.他可能是[l+1, r] 和[l, r-1]两个区间的结果. 或者当s[l] == s[r]时,区间[l+1, r-1]的结果再加上以s[l], s[r]为首尾的子序列. dp[l][r] = ans(dp[l][r-1], dp[l+1][r], s[l] + dp[l+1][r-1] + s[r])  dp存的是子序列,即一…

［抄题］: Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". [暴力解法]: 时间分…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Example 2:Input:…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Example 2:Input:…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Example 2:Input:…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Example 2:Input:…

Longest Palindromic Subsequence 题解 题目来源:https://leetcode.com/problems/longest-palindromic-subsequence/description/ Description Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 10…

1. Question Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1: Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Exam…

lc 516 Longest Palindromic Subsequence 516 Longest Palindromic Subsequence Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1: Input: "bbbab" Output: 4 One pos…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Example 2:Input:…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Example 2:Input:…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000. Example 1:Input: "bbbab" Output: 4 One possible longest palindromic subsequence is "bbbb". Example 2:Input:…

Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000.Example 1:Input:"bbbab"Output:4One possible longest palindromic subsequence is "bbbb".Example 2:Input:"c…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题思路 代码 刷题心得 日期 题目地址:https://leetcode.com/problems/longest-palindromic-subsequence/description/ 题目描述 Given a string s, find the longest palindromic subsequence's length in s. You ma…

题意:给定一个字符串,问删除一些字符,使得它成为一个最长回访串,如果有多个,输出字典序最小的那个. 析: 我们可以把原字符串反转,然后求两个串的LCS,就得到最长回文串,不过要注意一些细节. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <c…

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=465&page=show_problem&problem=2399 最长的很简单,将串翻转过来后求两个串的lcs就是答案.. 主要是字典序那里... 还是开string来比较吧.. 注意最后输出方案时用前半段推出后半段.(因为可能lcs时会重合...) #include <cstdio> #include…

题目链接:https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=16&page=show_problem&problem=1346 Dynamic programming 需要注意的是input里可能含有空行,一行空行也是一个string,所以如果用scanf("%s", string)是不能把空行存进string变量里的.需要用gets或者getli…

Problem C: Longest Common Subsequence Sequence 1: Sequence 2: Given two sequences of characters, print the length of the longest common subsequence of both sequences. For example, the longest common subsequence of the following two sequences: abcdgh…

例题5--9 数据库 Database UVa 1592 #include<iostream> #include<stdio.h> #include<string.h> #include<cmath> #include<string> #include<queue> #include<stack> #include<vector> #include<map> #include<set>…

题目链接:http://acm.hust.edu.cn/vjudge/contest/126708#problem/C 题意:这是一道求字符串的公共子串的最大长度的题目,用dp动态方程即可 if(a[i]==b[j]) dp[i][j]=dp[i-1][j-1]+1; else dp[i][j]=(dp[i][j-1]>p[j][i-1]?dp[i][j-1]:p[j][i-1]); 这题主要是要注意两个字符串是同一行输入,题目没说字符串的长度,用c不是dp数组开大了编译不了就是开小了运行错误,…

最长公共子序列,经典问题.算是我的DP开场题吧. dp[i][j]表示到s1的i位置,s2的j位置为止,前面最长公共子序列的长度. 状态转移: dp[i][j] = 0                                       (i == 0 || j == 0) dp[i][j] = dp[i-1][j-1] + 1                   (s1[i] == s2[j]) (此字符相等,说明此时最长公共子序列的长度等于他们之前的LCS(简称)长度加上这个相等的字…

题目大意 给定一个字符串,要求你删除尽量少的字符,使得原字符串变为最长回文串,并把回文串输出,如果答案有多种,则输出字典序最小的 题解 有两种解法,第一种是把字符串逆序,然后求两个字符串的LCS,并记录LCS,长度就等于最长回文串的长度,不过求出来的LCS不一定是回文串,例如下面这个例子 s = 1 5 2 4 3 3 2 4 5 1 reverse(s) = 1 5 4 2 3 3 4 2 5 1 LCS = 1 5 2 3 3 4 5 1 所以我们只需要LCS的前半段即可 代码: #incl…

回文子串dp,最小字典序的话需要记录一下,注意是string型的,不能只记录一个字符,因为可能出现相等的情况 #include<cstdio> #include<cstdlib> #include<algorithm> #include<cstring> #include<string> #define len first #define str second #define MAXN 1005 #define pii pair<int,i…

https://vjudge.net/problem/UVA-11404 题意: 给定一个由小写字母组成的字符串,删除其中的0个或多个字符,使得剩下的字母(顺序不变)组成一个尽量长的回文串.如果有多解,输出字典序最小的解. 思路: 首先,最长回文子串的长度可以通过正序字符串和逆序字符串进行LCS得出. 但是这道题目麻烦的是还要输出这个回文串,并且字典序得最小. 应用的主要还是LCS的思想方法,不过在进行状态转移的时候,再加上字符串的状态转移. 不过最后得到的字符串不一定是回文串,但是它的前一半肯…

This is the classic LCS problem. Since it only requires you to print the maximum length, the code can be optimized to use only O(m) space (see here). My accepted code is as follows. #include <iostream> #include <string> #include <vector>…