题目链接: https://leetcode.com/problems/count-different-palindromic-subsequences/description/ 730.Count Different Palindromic Subsequences 题意 给你一个只包含a.b.c.d字符的字符串,总共有多少个不重复的回文子序列. 题解 容易想到这题可以用动态规划的方法来解决. 1.dp[l][r][k]表示区间[l,r]内,以字符k+'a'结尾的回文子序列个数. 当k+'a'…

lc 730 Count Different Palindromic Subsequences 730 Count Different Palindromic Subsequences Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a string S i…

Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a string S is obtained by deleting 0 or more characters from S. A sequence is palindromic if it is equal…

Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a string S is obtained by deleting 0 or more characters from S. A sequence is palindromic if it is equal…

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 解题方法 记忆化搜索 动态规划 日期 题目地址:https://leetcode.com/problems/count-different-palindromic-subsequences/description/ 题目描述 Given a string S, find the number of different non-empty palindromic…

Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a string S is obtained by deleting 0 or more characters from S. A sequence is palindromic if it is equal…

Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a string S is obtained by deleting 0 or more characters from S. A sequence is palindromic if it is equal…

Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a string S is obtained by deleting 0 or more characters from S. A sequence is palindromic if it is equal…

突然很想刷刷题,LeetCode是一个不错的选择,忽略了输入输出,更好的突出了算法,省去了不少时间. dalao们发现了任何错误,或是代码无法通过,或是有更好的解法,或是有任何疑问和建议的话,可以在对应的随笔下面评论区留言,我会及时处理,在此谢过了. 过程或许会很漫长,也很痛苦,慢慢来吧. 编号 题名 过题率 难度 1 Two Sum 0.376 Easy 2 Add Two Numbers 0.285 Medium 3 Longest Substring Without Repeating C…

645. Set Mismatch The set S originally contains numbers from 1 to n. But unfortunately, due to the data error, one of the numbers in the set got duplicated to another number in the set, which results in repetition of one number and loss of another nu…