Solving Intersection of Two Arrays II with Two Pointers

✅Day 58 of #100DaysOfLeetCode 1.📌Problem: 2011. Final Value of Variable After Performing Operations 2.✅ Difficulty: Easy 3.📍Topic: Array 4.🎯 Goal: Given an array of strings operations containing a list of operations, return the final value of x after performing all the operations. 5.🧠key idea: Approach 1: Initialize a counter variable to zero. Iterate through the input array of operations. For each operation string, check if it represents an increment ("++X" or "X++"). If it does, increase the counter by one. Otherwise, it's a decrement, so decrease the counter by one. After checking all the operations, return the final value of the counter. #100DaysOfLeetCode #CodingChallenge #Java #ProblemSolving #SoftwareDevelopment #Developer #Programming #CodeNewbie #Tech #DataStructures #Algorithms #Array #LeetCodeChallenge #SoftwareEngineer #DailyChallenge

✅Day 59 of #100DaysOfLeetCode 📌Problem: Given a fixed-length integer array arr, duplicate each occurrence of zero, shifting the remaining elements to the right. 🟢 Difficulty: Easy 📍Topic: Array 🎯 Goal: To modify the input array in place by duplicating every zero and shifting other elements accordingly, without returning anything. 🧠key idea: Approach 1: Create a new result array to hold the modified elements. Iterate through the original array; if the element is a zero, add it twice to the result array. Otherwise, add the element once. Finally, copy the contents of the result array back into the original array. #100DaysOfCode #LeetCode #CodingChallenge #Java #DataStructures #Algorithms #ProblemSolving #Developer #SoftwareEngineering #CodeNewbie #Tech #Programming #ArrayManipulation #DuplicateZeros #Day59

✅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

#Day13 2 – Add Two Numbers Solved this classic linked list problem by implementing an efficient algorithm to add two numbers represented as reverse-digit linked lists. 💡 Approach: Used a dummy node to simplify list construction, iterated through both lists while handling different lengths, and maintained a carry value for proper digit summation. The solution elegantly handles cases where lists have different sizes and final carry propagation. #LeetCode #Java #LinkedList #DataStructures #Algorithms #ProblemSolving #Coding #Tech #SoftwareEngineering #DailyCoding #Programming

✅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

✅Day 79 of #100DaysOfLeetCode 1.📌Problem: Can Make Arithmetic Progression From Sequence 2.🟢 Difficulty: Easy 3.📍Topic: Arrays, sorting 4.🎯 Goal: Given an array of numbers, return true if the array can be rearranged to form an arithmetic progression; otherwise, return false. 5.🧠 Key idea: Approach 1: Sort the array to bring numbers in order. Calculate the common difference between the first two elements. Iterate through the array and check if the difference between consecutive elements matches the common difference. If any element does not satisfy the condition, return false; otherwise, return true. #LeetCode #100DaysChallenge #Programming #Coding #Java #Algorithms #CodingPractice #Developer #Tech #CodeNewbie #LearnToCode #ProblemSolving #DataStructures #Arithmetics #InterviewPreparation #CodingSkills #DailyCoding #LinkedInChallenge

✅Day 75 of #100DaysOfLeetCode 1.📌Problem: Given two strings s and t, return true if s is a subsequence of t, or false otherwise. A subsequence of a string is a new string formed by deleting some (can be none) of the characters without disturbing the relative position of the remaining characters. 2.🟢 Difficulty: Easy 3.📍Topic: Two Pointers 4.🎯 Goal: Check if a given string is a subsequence of another string. 5.🧠Key idea: Approach 1: Use two pointers to traverse both strings. Increment the pointer for s when a matching character in t is found. If all characters of s are matched in order in t, s is a subsequence of t. #LeetCode #100DaysOfCode #CodingChallenge #Programming #Java #DataStructures #Algorithms #StringManipulation #TwoPointers #InterviewPrep #LearnToCode #TechCareers #CodeDaily #ProblemSolving #Subsequence #Accepted

📌 Day 23/100 – Squares of a Sorted Array (LeetCode 977) 🔹 Problem: Given a sorted integer array (may contain negatives), return a new array of the squares of each number, sorted in non-decreasing order. 🔹 Approach (Two Pointers): Since negative values become positive when squared, the largest values will be at either end of the array. So we: Use left and right pointers Compare squares → place the larger one at the end of result array Move pointers inward and fill result from back to front This avoids sorting again and keeps the solution O(n). 🔹 Time & Space Complexity: ⏱️ Time: O(n) 💾 Space: O(n) (result array) 🔹 Key Learnings: ✅ Two-pointer technique helps avoid extra sorting ✅ Always think about value transformation (like negative → squared) ✅ Filling from the back is a smart trick when maintaining sorted order #100DaysOfCode #LeetCode #Java #DSA #ProblemSolving #CodingJourney #TwoPointers #Programming