Non overlapping palindromic subsequences hackerrank Aug 10, 2020 · Longest Palindromic Substring - Python - Leetcode 5 NeetCode 1M subscribers Subscribe LeetCode solutions in any programming language730. The Palindromic Strength of a String is defined as largest possible product of length of two non-overlapping palindromic Substring of the String. You randomly swap two characters in a string until the string becomes a palindrome. Insert characters in a string so that length longest palindromic subsequence increases by at least K. Day 28: Maximum Non-Overlapping Odd Palindrome Sum Today’s #nationskillup challenge was about finding the maximum possible sum of the lengths of any two non-overlapping palindromic substrings of Return the maximum possible product of the lengths of the two non-intersecting palindromic substrings. Solutions in C, C++, Java, and Python included. The subsequences with the maximum score are atta (length = 4) and either c or t (length = 1), resulting in a score of 4x1 = 4. The solutions to LeetCode problems are posted at the discussion sections in each solved problem folder. The substrings do not overlap, that is for any two substrings s[i. He has a list of strings, , where each string, , consists of lowercase English alphabetic letters. Return the maximum number of substrings in an optimal selection HackerRank Algorithms Solutions This repository contains solutions to the Algorithms Domain part of HackerRank. Jul 10, 2025 · If the string is not a palindrome, the strategy involves removing maximal palindromic subsequences in each step. Maximum Product of the Length of Two Palindromic Subsequences - Leetcode 2002 - Python NeetCode 1. It only takes a minute to sign up. The task is to count the number of pairs of the non-overlapping palindromic sub-strings. Example Either remove 'b' at index or 'c' at index . , in an exercise) as another example of a problem solvable by dynamic programming. A subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements. j] and s[k. Thus, we print 0 on a new line. As another example, if the given sequence is "BBABCBCAB", then the output should be 7 as "BABCBAB" is the longest palindromic subsequence in it. Find all the pairs (i, j) such that substring s [i … j] is a palindrome. We can use dynamic programming to precompute all palindromic substrings, then greedily select the earliest non-overlapping palindromes. A substring is a contiguous sequence of characters in a string. In-depth solution and explanation for LeetCode 2002. com/problems/remove-palindromic-subsequences/ Problem Given a string s, find two disjoint palindromic subsequences of s such that the product of their lengths is maximized. The Algorithms Domain Falls under a broader Problem Solving Skill Set in HackerRank which consists of both Data Structures and Algorithms. There may be more than one solution, but any will do. Nov 26, 2017 · Source Leetcode Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. Maximum Number of Non-overlapping Palindrome Substrings in Python, Java, C++ and more. Can you solve this real interview question? Maximum Number of Non-overlapping Palindrome Substrings - You are given a string s and a positive integer k. For example, "abab", "aa" are square strings, while "aaa", "abba" are not. "BBBBB" and "BBCBB" are also palindromic subsequences of the given sequence, but not the longest ones. Solution Explanation: Maximum Number of Non-Overlapping Palindrome Substrings This problem asks to find the maximum number of non-overlapping palindromic substrings within a given string s, where each substring's length must be at least k. Jul 23, 2025 · The idea is to recursively generate all possible subsequences of the given string s and find the longest palindromic subsequence. Note Two palindromic subsets are considered to be different if their component characters came from different indices in the original string. Return the maximum possible product of the lengths of the two non-intersecting palindromic substrings. By n1e2m3, history, 5 years ago, given a string S. Find the total number of non-decreasing subsequences present in the array. g. Nov 24, 2022 · Note: "t" is empty for even length palindromic strings Calculate in how many ways "str" can be made and then multiply with "t" (number of single characters left out). In other words, score (s) = max (length (a) x length (b)). However, one can easily modify the standard LCS dynamic-programming algorithm to return an LCS that is a palindrome (given X and its reverse). Two palindromic subsets are considered to be different if their component characters came from different indices in the original string. Count the number of palindromic subsequences. - haymachandhiran/hackerrank_Python_Codes Given a string, find the length of the largest palindromic substring. A string is said to be palindrome if the reverse of the string is the same as the string. If the word is already a palindrome or there is no solution, return -1. A subsequence of a string is obtained by deleting zero or more characters from the string. A string is a palindrome when it reads the same backward as forward. Aug 29, 2025 · Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more. Jul 31, 2025 · Given a string s consisting of lowercase English letters, find the maximum possible sum of the lengths of any two non-empty and non-overlapping palindromic substrings of odd length. Problem: Solve the "Maximum Length of Non-Overlapping Palindromic Subsequences" problem where you find the maximum number of non-overlapping palindromic subsequences using dynamic programming. . The fun score, for selecting two subsequences, is the product of their respective lengths. A sequence is palindromic if it is equal to the sequence reversed Problem Explanation Given a string s of length n and an integer k, you need to find the number of distinct palindromic subsequences of s with a length greater than or equal to k. given a string S. - keineahnung2345/leetcode-cpp-practices What is the sum of the minimum elements of all unordered non-intersecting contiguous subsequence pairs? A code bank to questions on HackerRank and HackerEarth. Finding the maximum product of two non-overlapping palindromic subsequences involves identifying subsequences that are palindromic and calculating their products. What is Longest Palindromic Subsequence: A longest palindromic subsequence is a sequence that appears in the same relative order, but not necessarily contiguous (not substring) and palindrome in nature ( means the subsequence will Number of palindromic subsequences of length k where k <= 3. The task was to find the maximum product of size of the two non-overlapping palindromic subsequences that could be formed using the given string. If there are multiple answers, then find the first appearing substring. Examples: Input: str = "abbaccd" Output: bb cc d Explanation: The Jan 1, 2025 · Solution Method 1 – Dynamic Programming + Greedy Intuition We want to select the maximum number of non-overlapping palindromic substrings of length at least k. Examples: Input: s = "forgeeksskeegfor" Output: "geeksskeeg" Explanation: The longest substring that reads the same forward and backward is "geeksskeeg". Oct 1, 2024 · This is the most optimized approach where we use a 2D dynamic programming table to store the number of palindromic subsequences for every substring of the given string. e. Contribute to fraglord94/hackerrank-solutions development by creating an account on GitHub. Select a set of non-overlapping substrings from the string s that satisfy the following conditions: * The length of each substring is at least k. A palindrome is a sequence that reads the same backward as forward May 22, 2023 · The goal is to find the two non-overlapping palindromic subsequences with the maximum score. A substring that contains a certain character Palindrome Subsequences For a string \ ( s \) which consists only of characters ' 0 ' and ' 1 ', find the number of subsequences of length 5 which are palindromes. What is the expected number of swaps you will make? The Palindromic Strength of a String is defined as largest possible product of length of two non-overlapping palindromic Substring of the String. Palindromic Substrings - Given a string s, return the number of palindromic substrings in it. Better than official and forum solutions. Nov 17, 2020 · I am solving a problem for Hackerrank where I have to count the number of palindromes in a given string. A sequence is palindromic if it is equal to the sequence reversed Problem Description Given a string s, count how many different non-empty palindromic subsequences exist in s. Given a string s, return the number of different non-empty palindromic subsequences in s. The score obtained is the product of the length of these 2 subsequences. n-1] be the input sequence of Solving code challenges on HackerRank is one of the best ways to prepare for programming interviews. The task is to count the non-overlapping pairs of palindromic sub-strings S1 and S2 such that the strings should be S1 [L1R1] and S2 [L2R2] where 0 ? L1 ? R1 < L2 ? R2 < N. Problem Description Given a string s, count how many different non-empty palindromic subsequences exist in s. Count Different Palindromic Subsequences. Return the maximum number of substrings in an optimal selection. Nov 16, 2024 · To avoid overlapping we have to ensure that the length of suffix is less than (j-i) at any instant. To do so, create two counters low and high and set them to point to first and last character of string s. Your first subsequence (that is, the one that contains the lowest-numbered element) can start at element 0, or at element 1, or at element 2, or at element 3, or at element Two palindromic subsequences are considered different if they occur in different positions or have different compositions. A subsequence of a string S is obtained by deleting 0 or more characters from S. A sequence is palindromic if it is equal to the sequence How many substrings of a string are square strings, i. By using DP with memoization, we can efficiently count unique palindromic subsequences in all substrings, leveraging overlapping subproblems. Since the answer may be very large, return it modulo 10 9 + 7. Solving code challenges on HackerRank is one of the best ways to prepare for programming interviews. Select a set of non-overlapping substrings from the string s that satisfy the following conditions: The length of each substring is at least k. Including problem statement, solution, runtime and complexity analysis. A subsequence is a sequence that can be derived from the string by deleting some (or no) characters without changing the order of the remaining characters. Examples: Input: s = "aaa" Output: 5 All possible pairs are (s [0], s [1]), (s [0], s [2]), (s [0], s [1, 2 Can you solve this real interview question? Count Different Palindromic Subsequences - Given a string s, return the number of different non-empty palindromic subsequences in s. Jun 21, 2022 · Given a string S. In the first case: The maximum sum for both types of subsequences is just the sum of all the elements since they are all positive. Return the maximum possible product of the lengths of the two palindromic Join over 11 million developers in solving code challenges on HackerRank, one of the best ways to prepare for programming interviews. A palindrome is a sequence that reads the same backward as forward Join over 11 million developers in solving code challenges on HackerRank, one of the best ways to prepare for programming interviews. The string s consists only of the characters 'a', 'b', 'c', and 'd'. Count Palindromic Subsequences in Python, Java, C++ and more. * Each substring is a palindrome. In this post, we will solve Maximum Palindromes HackerRank Solution. j] and s[x. We need to first identify all palindromic subsequences in the string, and then evaluate the maximum product of the lengths of two such subsequences that do not share any characters. Aug 2, 2023 · There is no way to choose non-empty subsequences such that their concatenation results in a palindrome, as each string contains unique characters. Each substring is a palindrome. Sep 17, 2025 · The Longest Palindromic Subsequence (LPS) problem is finding the longest subsequences of a string that is also a palindrome. A subsequence of a string is a Hi HackerRank team, I’m working on the “Build Longest Palindrome” problem and encountered an issue with Test Case 2. Return the maximum possible product of the lengths of the two palindromic subsequences. 2. Intuitions, example walk through, and complexity analysis. A substring is a contiguous sequence of characters within the string. What is the sum of the minimum elements of all unordered non-intersecting contiguous subsequence pairs? Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. However, Test Case 2 expects a palindrome 'oozlzoo', which is not constructible from any combination of substrings from a and b — this violates the LeetCodee solution for problem 730. Other palindromes like "kssk" or "eeksskee" are shorter. Minimum deletions to make a string a palindrome. A subsequence of a string is obtained by The longest palindromic subsequence (LPS) problem on a single input string is sometimes presented (e. HackerRank Solutions in Python3. This pattern is a classic Dynamic Programming (DP) problem because the solution depends on substrings and overlapping subproblems. If the solved Leetcode problem is one of the problems asked by MAANG companies then that solution of specific company is added as my GitHub solution found through Here is my solution in java, C, C++, Csharp HackerRank Shashank and the Palindromic Strings Given a string s, return the number of different non-empty palindromic subsequences in s. A palindrome is a string that is the same forward and backward. Aug 13, 2021 · Q2) This was a Dynamic Programming question. Otherwise, return the index of a character to remove. Input: s = "Geeks" Output: "ee" Explanation Count distinct palindromic subsequences in a string efficiently using dynamic programming and divide-and-conquer. Apr 13, 2025 · The idea is to generate all possible subsequences of the given string str, and store them in a HashSet to find the count of distinct subsequences. Firstly you should traverse the dp table to find out the length of longest palindromic subsequences using bottom up approach, then you can calculate the max product by multiplying dp [i] [j] with dp [j+1] [n-1] : Given below is the code in C++; You can loop through all non-overlapping palindromic subsequences and return the maximum value. Contribute to rdsiva/hackerrank development by creating an account on GitHub. Given a string, how many (non-empty) subsequences of the string are square strings? A subsequence of a string can be obtained by deleting zero or more characters from it, and maintaining the A greedy strategy is then used to move through the string: at the current index, find the earliest ending palindrome (of length at least k) and jump to its end + 1. Solving the LPS problem on a string of length n using Given string S, find two palindromic subsequences such that product of length of these is maximal and these don't overlap Insert characters in a string so that length longest palindromic subsequence increases by at least K. Objective: Given a string, find a longest palindromic subsequence in it. Since the answer may be very large, return it modulo 10^9 + 7. This process can be broken down into several steps: identifying palindromic subsequences, ensuring they do not overlap, and maximizing the product. Find the number of different non-empty palindromic subsequences in a given string. The repository is constantly updated when Python or SQL solution to the problem found at LeetCode or HackerRank is solved. Longest Palindromic Subsequence - Given a string s, find the longest palindromic subsequence's length in s. A sequence is palindromic if it is equal to the sequence reversed Jul 23, 2025 · Easy Problems on Subsequences: Given a number as a string, find the number of contiguous subsequences which recursively add up to 9 Minimum number of palindromic subsequences to be removed to empty a binary string Find largest word in dictionary by deleting some characters of given string Longest Common Anagram Subsequence Oct 3, 2025 · The idea is to identify all palindromic substrings in a given string using a dynamic programming method, then eliminate duplicates by leveraging the KMP algorithm, and finally print the distinct palindromes along with their count. for example, 1) s = “abcab” ans = 3*2 = 6 two palindromic sequence are “aca” and “bb” 2 ) s = nriatdoiarn ans = 5*5 = 25 two Codeforces. String t is a palindrome when t = t r e v ( t r e v is a reversed string for t ). , the subsequence should read the same forwards and backwards. Example 1: Input: s = "babad" Output: "bab" Explanation: "aba" is also a valid answer. Shashank wants to count the number of ways of choosing non-empty subsequences such that the following conditions are satisfied: is a subsequence of string , is a subsequence of string , is a subsequence of string , , and is a Count Different Palindromic Subsequences Given a string s, return the number of different non-empty palindromic subsequences in s. Apr 7, 2024 · You will be Champ in Subarrays, Subsequences, and Subsets Problems after completing this set of problems. Programming competitions and contests, programming communityBy n1e2m3, history, 5 years ago, given a string S. Answer: To find the maximum product of two non-overlapping palindromic subsequences from a given string, we can break the problem down into a few steps. My algorithm correctly constructs valid palindromes by combining substrings from a and b, and it passes all other cases. Function Can you solve this real interview question? Longest Palindromic Substring - Given a string s, return the longest palindromic substring in s. <br/> Solving code challenges on HackerRank is one of the best ways to prepare for programming interviews. Count Different Palindromic Subsequences - LeetCode Wiki Home Cracking the Coding Interview Focused Training Contest LeetCode Wiki doocs/leetcode Home LeetCode LeetCode Last update: May 24, 2025 Translated From: e-maxx. , can be made by concatinating two copies of some other string Determine if the substrings of two strings can be concatenated into a palindromic string. This problem (Maximum Palindromes) is a part of HackerRank Problem Solving series. In the second case: The subarray is the subarray with the maximum sum, and is the subsequence with the maximum sum. You have to select exactly two non- overlapping palindromic subsequences A and B from the string to maximize the fun score. Can you solve this real interview question? Unique Length-3 Palindromic Subsequences - Given a string s, return the number of unique palindromes of length three that are a subsequence of s. Dec 31, 2023 · Given a string s, return the number of different non-empty palindromic subsequences in s. Contribute to yznpku/HackerRank development by creating an account on GitHub. A substring is a contiguous sequence of characters within a string. 🚀 https://neetcode. They take a word composed of lowercase English letters and try to get the maximum possible score by building exactly 2 palindromic subsequences. For the sake of exposition, let's assume that you have a list of 10 elements (numbered 0 through 9), and you need to select 3 subsequences, each of length 2. here, non overlapping means only indexes are non overlap. In-depth solution and explanation for LeetCode 2484. Sep 14, 2023 · Given a string S and a positive integer K, The task is to maximize the product of the length of non-overlapping palindromic substrings each of length at least K from the string S. Dec 7, 2018 · You can loop through all non-overlapping palindromic subsequences and return the maximum value. Example 1: Input: s = "abaccdbbd", k = 3 Can you solve this real interview question? Count Different Palindromic Subsequences - Given a string s, return the number of different non-empty palindromic subsequences in s. The problem differs from the problem of finding the longest palindromic subsequence. What is the sum of the minimum elements of all unordered non-intersecting contiguous subsequence pairs? What is the sum of the minimum elements of all unordered non-intersecting contiguous subsequence pairs? Solving code challenges on HackerRank is one of the best ways to prepare for programming interviews. Maximum Product of the Length of Two Palindromic Subsequences - LeetCode Wiki Home Cracking the Coding Interview Focused Training Contest LeetCode Wiki doocs/leetcode Home LeetCode LeetCode :pencil: Python / C++ 11 Solutions of All 468 LeetCode Questions - stjordanis/LeetCode33 Given a string s, return the number of unique palindromes of length three that are a subsequence of s. Manacher's Algorithm helps us find the longest palindromic substring in the given string. Typical Problems: Find the length of the longest palindromic subsequence (LPS). Contribute to sirjansingh310/hackerrank-codechef-geeksforgeeks-topcoder-solutions development by creating an account on GitHub. A palindromic subsequence is a subsequence that reads the Jan 25, 2020 · This is the solution for problem number 1 of leetcode weekly contest 173https://leetcode. You need to return the length of the longest palindromic subsequence in A. A subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters. Jan 28, 2020 · 1520. Then print this number modulo 10**9 + 7 on a new line. A palindrome is a string that reads the same forwards and backwards. Minimum insertions to make a string a palindrome. Aug 14, 2021 · You are given a 0-indexed string s and are tasked with finding two non-intersecting palindromic substrings of odd length such that the product of their lengths is maximized. Contribute to jhflorey/HackerRank development by creating an account on GitHub. The majority of the solutions are in Python 2. Return the maximum number of substrings in an optimal selection Shashank loves strings, but he loves palindromic strings the most. A sequence is palindromic if it is equal to the sequence reversed. HackerRank solutions in Java/JS/Python/C++/C#. 01M subscribers Subscribe Jan 3, 2025 · Unique Length-3 Palindromic Subsequences - Leetcode 1930 - Python NeetCodeIO 271K subscribers 451 Jan 25, 2011 · Every longest palindromic subsequence of X is also a longest common subsequence of X and its reverse, but the converse doesn't hold. Example 2: Input: s = "cbbd" Output: "bb" Constraints: * 1 <= s. l], either j < k or i > l is true. The two subsequences are disjoint if they do not both pick a character at the same index. A palindrome is a sequence that reads the same backward as forward Day 28: Maximum Non-Overlapping Odd Palindrome Sum Today’s #nationskillup challenge was about finding the maximum possible sum of the lengths of any two non-overlapping palindromic substrings of LeetCode solutions in any programming language2002. If multiple solutions with the same number of substrings exist, then print the one with the minimum total length. I have the following code which counts the number of palindromes accurately but times out for large strings. length <= 1000 * s consist of only digits and English letters. Since the answer may be very large, return it modulo 109 + 7. More precise statement In the worst case string might have up to O (n 2) palindromic Maximum Product of the Length of Two Palindromic Subsequences Given a string s, find two disjoint palindromic subsequences of s such that the product of their lengths is maximized. Square Subsequences A string is called a square string if it can be obtained by concatenating two copies of the same string. for example, 1) s = “abcab” ans = 3*2 = 6 two palindromic sequence are “aca” and “bb” 2 ) s = nriatdoiarn ans = 5*5 = 25 two palindromic sequences are “nitin” and ( “radar” or Given a string of lowercase letters in the range ascii [a-z], determine the index of a character that can be removed to make the string a palindrome. Can you solve this real interview question? Maximum Number of Non-Overlapping Substrings - Given a string s of lowercase letters, you need to find the maximum number of non-empty substrings of s that meet the following conditions: 1. The maximum value of suffix (i, j) provides the length of the longest repeating substring and the substring itself can be found using the length and the starting index of the common suffix. Example 1: Input: s = "abc" Output: 3 Explanation: Three palindromic strings: "a", "b", "c". Maximum Product of the Length of Two Palindromic Subsequences in Python, Java, C++ and more. This repository contains efficient hackerrank solutions for most of the hackerrank challenges including video tutorials. Aug 2, 2025 · Intuition The problem asks for the count of distinct palindromic subsequences. Note that even if there are multiple ways to obtain the same subsequence, it is still only counted once. A Computer Science portal for geeks. This two-phase approach (DP for palindromic checks and greedy selection) ensures the selected substrings are non-overlapping and maximizes their count. The Algorithms Domain is further Divided into the following sub-domains. You are given an array of integers of size N. Join over 11 million developers in solving code challenges on HackerRank, one of the best ways to prepare for programming interviews. 1) Optimal Substructure: Let X [0. Since subsequences can overlap and repeat, we need to avoid double-counting. Dec 8, 2018 · A subsequence is a group of characters chosen from a list while maintaining their order. - wimpywarlord/hacker_earth_and_hacker_rank_solutions This repository contains the solutions for hackerrank algorithms in Python3. Can you solve this real interview question? Count Different Palindromic Subsequences - Given a string s, return the number of different non-empty palindromic subsequences in s. In-depth solution and explanation for LeetCode 2472. For instance, the subsequences of abc are [a,b,c,ab,ac,bc,abc] The score of string s is the maximum product of two non-overlapping palindromic subsequences of s that we_ll refer to as a and b. The LPS problem asks to find a longest subsequence of a string that is a palindrome, i. A subsequence of a string S is obtained by deleting Can you solve this real interview question? Maximum Product of the Length of Two Palindromic Subsequences - Given a string s, find two disjoint palindromic subsequences of s such that the product of their lengths is maximized. Jul 31, 2024 · For each query, find and print the number of ways Shashank can choose N non-empty subsequences satisfying the criteria above, modulo 10 to power 9 plus 7, on a new line. y], either j < x or i > y is true. For example, “abba” is a palindrome, but “abbc” is Given string S, find two palindromic subsequences such that product of length of these is maximal and these don't overlap Solving code challenges on HackerRank is one of the best ways to prepare for programming interviews. for example, 1) s = “abcab” ans = 3*2 = 6 two palindromic sequence are “aca” and “bb” 2 ) s = nriatdoiarn ans = 5*5 Oct 3, 2025 · Given a string s, find the longest substring which is a palindrome. Mar 15, 2025 · The key to the solution is to know how many solutions are there. How to get the maximum value of a palindromic sequence? A string is palindromic if it reads the same forward and backward. To do so, create a HashSet to store the subsequences, and call a recursive function for all the indices of the string, starting from the 0th index. The minimum number of steps for any non-palindromic string s can be intuitively understood as follows: If s only consists of one type of character (all 'a's or all 'b's), then it is a palindrome and can be removed in one step. You are given a string s (0-indexed) and need to find two non-overlapping palindromic substrings, both with odd lengths, such that the product of their lengths is as large as possible. A subsequence of a Jul 23, 2025 · Given string str consisting of lowercase letters, the task is to find the maximum number of non-overlapping substrings such that each substring contains all occurrences of its characters from the entire string. Jul 23, 2025 · Given a sequence, find the length of the longest palindromic subsequence in it. io/ - A better way to prepare for Coding InterviewsSolving Leetcode 516 - Longest Palindromic Subsequence, today's daily leetcode problem Oct 21, 2021 · Problem Statement Given a string S, find the common palindromic sequence ( A sequence that does not need to be contiguous and is a palindrome), which is common in itself. Includes Python, Java, C++, JavaScript, and C# solutions. ru Manacher's Algorithm - Finding all sub-palindromes in O (N) Statement Given string s with length n . Palindromic string maximum product interview DP question help By n1e2m3, history, 6 years ago, given a string S. Maximum Number of Non-Overlapping Substrings (Medium) Given a string s of lowercase letters, you need to find the maximum number of non-empty substrings of s that meet the following conditions: The substrings do not overlap, that is for any two substrings s[i. Find the solution of Count Different Palindromic Subsequences Leetcode question with step by step explanation in 3 approaches and 3 solutions in languages like Java, CPP, Python. you have to find maximum product of length of two non overlapping palindromic sequence. uer igk coppe wgrpc viyiu isnnf sfzmeyd jqygib ume dquqeuy dneex zxuk qgjxsrzkt hcsja cetu