classSolution {public:intcountPalindromicSubsequences(stringS) {//dp[i][j] 表示 s[i...j] 包含的子序列个数intn =S.size(); vector<vector<int>> pos(4, vector<int>()); vector<vector<int>> dp(n, vector<int>(n,0));for(inti =0; i < n; i++) { pos[S[i]-'a'].push_back(...
code 1/*2Recursion with memoization3Time complexity: O(n^2)4Space complexity: O(n^2)5*/67classSolution {8privateint[][] memo;9//requirement: "return that number modulo 10^9 + 7"10privatestaticfinalintkMod = 1000000007;11publicintcountPalindromicSubsequences(String S) {12intn =S.length(...
在之前那道Longest Palindromic Subsequence中要我们求最长的回文子序列,我们需要逆向遍历dp数组,当s[i]和s[j]相同时,长度为中间部分的dp值加2,否则就是左边值和下边值中的较大值,因为是子序列,不匹配就可以忽略当前字符。而对于回文子串的问题,比如Longest Palindromic Substring和Palindromic Substrings,一个是求最...
3786-longest-palindromic-subsequence-after-at-most-k-operations 225. Implement Stack using Queues 2483. Minimum Penalty for a Shop 2707. Extra Characters in a String 338. Counting Bits 403. Frog Jump 62. Unique Paths README.md stats.jsonBreadcrumbs Leetcode /2057-count-salary-categories / 2057...
在之前那道Longest Palindromic Subsequence中要求最长的回文子序列,需要逆向遍历 dp 数组,当 s[i] 和 s[j] 相同时,长度为中间部分的 dp 值加2,否则就是左边值和下边值中的较大值,因为是子序列,不匹配就可以忽略当前字符。而对于回文子串的问题,比如Longest Palindromic Substring和Palindromic Substrings,一个是...
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+...
1classSolution {2func countPalindromicSubsequences(_ S: String) ->Int {3vararr:[Character] =Array(S)4varn:Int =S.count5varM:Int = Int(1e9 +7)6vardp:[[Int]] = [[Int]](repeating:[Int](repeating:0,count:n),count:n)7foriin0..<n8{9dp[i][i] =110}11forlenin1..<n12{13for...
原题链接在这里:https://leetcode.com/problems/count-different-palindromic-subsequences/ 题目: Given a string S, find the number of different non-empty palindrom
Return the number of teams you can form given the conditions. (soldiers can be part of multiple teams). Example 1: Input: rating = [2,5,3,4,1] Output: 3 Explanation: We can form three teams given the conditions. (2,3,4), (5,4,1), (5,3,1). ...