"Day 75: Check if a string is a subsequence of another using two pointers"

✅Day 74 of #100DaysOfLeetCode 1.📌Problem: Reverse Vowels of a String 2.🟩 Difficulty: Easy 3.📍Topic: Two Pointers 4.🎯 Goal: Given a string, reverse only the vowels in the string and return the modified string. Vowels include 'a', 'e', 'i', 'o', 'u' in both lower and upper cases. 5.🧠key idea: Approach 1: Use two pointers, one starting from the beginning and one from the end. Move towards each other, swap the vowels found at each pointer, and continue until all vowels are reversed. #LeetCode #CodingChallenge #100DaysOfCode #Algorithms #TechCareers #CodeNewbie #WomenWhoCode #Java #Programming #DailyCoding #Developer #InterviewPrep #TwoPointers #DataStructures #LearnToCode #ProblemSolving

✅ Day 122: Interleaved Strings Today’s #nationskillup challenge was a classic Dynamic Programming problem 🎯 — focused on checking whether a string s3 is formed by interleaving s1 and s2 while preserving the order of characters. ⚡ Problem Statement: You are given three strings: s1, s2, and s3. Check if s3 can be formed by interleaving characters of s1 and s2 without changing the relative order of characters in each string. 🧠 Conditions for a valid interleaving: Characters from s1 must appear in order in s3. Characters from s2 must appear in order in s3. Length of s3 must equal s1.length + s2.length. 🧪 Example: Input: s1 = "AAB", s2 = "AAC", s3 = "AAAABC" Output: true Explanation: s3 contains all characters of s1 and s2 in the same order. 💡 Approach Summary: This is a DP on strings problem. We maintain a 1D DP array where dp[j] represents whether s3 up to index (i + j – 1) can be formed using s1 up to i and s2 up to j. We check two possibilities at each step: ✔ Take a character from s1 ✔ Take a character from s2 Space is optimized from O(n × m) to O(m) using two 1D arrays. Time Complexity: O(n × m) Space Complexity: O(m) Thanks to GeeksforGeeks and Sandeep Jain Sir for the amazing problem patterns that build strong DP intuition! Shoutout to Tarun Seshank Gorisi for keeping the #nationskillup streak blazing 🔥 📚 Course Link: https://lnkd.in/gG3G2QFW #skillupwithgfg #nationskillup #DynamicProgramming #DP #Strings #Java #GeeksforGeeks #CodingChallenge #CodeEveryday

✅ Day 122: Interleaved Strings Today’s #nationskillup challenge was a classic Dynamic Programming problem 🎯 — focused on checking whether a string s3 is formed by interleaving s1 and s2 while preserving the order of characters. ⚡ Problem Statement: You are given three strings: s1, s2, and s3. Check if s3 can be formed by interleaving characters of s1 and s2 without changing the relative order of characters in each string. 🧠 Conditions for a valid interleaving: Characters from s1 must appear in order in s3. Characters from s2 must appear in order in s3. Length of s3 must equal s1.length + s2.length. 🧪 Example: Input: s1 = "AAB", s2 = "AAC", s3 = "AAAABC" Output: true Explanation: s3 contains all characters of s1 and s2 in the same order. 💡 Approach Summary: This is a DP on strings problem. We maintain a 1D DP array where dp[j] represents whether s3 up to index (i + j – 1) can be formed using s1 up to i and s2 up to j. We check two possibilities at each step: ✔ Take a character from s1 ✔ Take a character from s2 Space is optimized from O(n × m) to O(m) using two 1D arrays. Time Complexity: O(n × m) Space Complexity: O(m) 🤝Thanks GeeksforGeeks and Sandeep Jain Sir for the amazing problem patterns that build strong DP intuition! Shoutout to Jagan Mohan Jangam for keeping the #nationskillup streak blazing 🔥 📚 Course Link: https://lnkd.in/gyueNByH #skillupwithgfg #nationskillup #DynamicProgramming #DP #Strings #Java #GeeksforGeeks #CodingChallenge #CodeEveryday

Ever debugged for hours only to realize you were comparing Strings with == instead of .equals()?  You're not alone. 🤦♂️ The culprit? Java's String Pool - a memory optimization that trips up even experienced developers. I just wrote a deep dive into: ✅ How String Pool actually works behind the scenes ✅ Why comparing the same content with == sometimes returns true, sometimes false ✅ The intern() method and when to use it ✅ Real performance benchmarks ✅ Common pitfalls that waste memory Practical code examples included. 5-minute read. Read here: https://lnkd.in/g4emECJM #Java #Coding #Programming #SoftwareDevelopment #SoftwareEngineering

✅Day 80 of #100DaysOfLeetCode 1.📌Problem: Set Mismatch You are given an array that represents a set of integers from 1 1 to n n, but due to an error, one number is duplicated and another is missing. The task is to find the duplicated number and the missing number and return them as an array. 2.🟢 Difficulty: Easy 3.📍Topic: Hashing,Array 4.🎯 Goal: Find the number that occurs twice and the number that is missing, then return them in an array. 5.🧠 key idea: Approach 1: Use a HashMap to count occurrences of each number in the input array. Identify the duplicated number by finding the one which appears twice. Compute the total sum expected (n(n+1)/2 n(n+1)/2) and compare with the actual sum (excluding the duplicate). The missing number equals the difference between the expected total and the corrected actual sum. Return the duplicate and missing numbers as the result array. #LeetCode #100DaysOfCode #CodingChallenge #Java #Programming #InterviewPrep #Algorithms #DataStructures #Hashing #ProblemSolving #Array #SoftwareEngineering #TechCareers #LearnToCode #CodeNewbie #DailyCode #ChallengeYourself

✅Day 68 of #100DaysOfLeetCode 1.📌Problem: Given two binary strings a and b, return their sum as a binary string. 2.🟢 Difficulty: easy 3.📍Topic: Add Binary, string 4.🎯 Goal: Add two binary strings and output the result as a binary string. 5.🧠Key idea: Approach 1: Use two pointers moving from right to left on both strings, add corresponding digits and carry, append the sum modulo 2 to the result, and handle final carry if any. Reverse the result at the end to get the correct binary output. #100DaysOfCode #LeetCode #Programming #Coding #Java #SoftwareDevelopment #ProblemSolving #Developer #CodeNewbie #CodingPractice #DataStructures #Algorithms #WebDevelopment #Tech #Python #Computersciencebest

✅Day 78 of #100DaysOfLeetCode 1.📌Problem: Find the Difference Given two strings s and t, where t is generated by shuffling s and adding one extra letter at a random position, return the letter that was added. 2.🟢 Difficulty: Easy 3.📍Topic: Strings 4.🎯 Goal: Find the extra character that was added to string t after shuffling and insertion. 5.🧠Key idea: Approach 1: Use the XOR operation to efficiently find the difference. Iterate over both strings, XOR all characters together, and the result will be the added character. This works because XOR-ing identical characters cancels them out, leaving only the unique/added character. #LeetCode #100DaysChallenge #Programming #Coding #CodeNewbie #Java #Tech #SoftwareEngineering #ProblemSolving #Developer #DailyChallenge #HashTable #Algorithms #CodingInterview #LearnToCode

✅Day 62 of #100DaysOfLeetCode 📌Problem: You are given a sorted array consisting of only integers where every element appears exactly twice, except for one element which appears exactly once. 🟠 Difficulty: Medium 📍Topic: Array, Binary Search 🎯 Goal: Return the single element that appears only once in O(log n) time and O(1) space. 🧠key idea: Approach 1: The problem can be efficiently solved using a modified binary search. The core logic relies on the properties of the sorted array. If we are at an even index, its duplicate pair should be at the next (odd) index. If we are at an odd index, its pair should be at the previous (even) index. By examining the middle element and its neighbor, we can determine if the single, non-duplicated element lies in the left or right half of the array, allowing us to discard one half in each step and achieve a logarithmic time complexity. #100DaysOfCode #LeetCode #CodingChallenge #Java #DataStructures #Algorithms #BinarySearch #ProblemSolving #SoftwareDeveloper #TechJobs #DeveloperLife #CodeNewbie #Programming #LearnToCode #JobSeekers

Recently, I got curi🤔us about how high-level languages like Go, Java, or Rust are actually built. Do they all start from assembly? Turns out, not all high-level languages start from assembly. Take Go (Golang) as an example, the first Go compiler that turned Go code into machine code was written in C, not assembly. As Go matured, this C-based compiler was replaced by a new compiler written in Go itself. This fascinating process is called bootstrapping, it’s when a programming language’s compiler is written in the same language it compiles. In other words, the language learns to build itself. #golang #rustlang #bootstrapping #compiler #java #SoftwareDevelopment #Programming #GoDeveloper #SoftwareEngineering

✅Day 83 of #100DaysOfLeetCode 📌Problem: Given a binary array and an integer k, return true if all 1's are at least k places away from each other, otherwise return false. 🟢 Difficulty: Easy 📍Topic: Array 🎯 Goal: Check if all 1's in the array are at least k positions apart. 🧠 Key idea: Approach 1: Iterate through the array, track the position of the previous 1, and for each new 1, calculate the distance from the previous 1. If the distance is less than k at any point, return false. Otherwise, return true after the loop ends. #LeetCode #CodingChallenge #100DaysOfCode #DataStructures #Algorithms #Array #Java #CodingInterview #Programmers #DailyCoding #CodeNewbie #TechCareers #ProblemSolving #CodeChallenge