Java DSA Day 17: Array Rotation with Reversal Algorithm

🚀 Day 30 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Sorting Technique 🧩 Problem Solved: Longest Common Prefix Problem: Given an array of strings, find the longest common prefix shared among all the strings. Approach: Sorted the array of strings and compared only the first and last strings. Since sorting groups similar prefixes together, the common prefix between these two strings represents the common prefix for the entire array. Key Learning: ✔️ Using sorting to simplify string comparison problems ✔️ Observing patterns to reduce unnecessary checks ✔️ Efficient prefix detection in string arrays If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency 

🚀 Day 34 / 180 – DSA with Java 🚀 📘 Topic Covered: Arrays & Basic Construction 🧩 Problem Solved: Concatenation of Array Problem: Given an integer array nums, create a new array that contains the elements of nums twice in sequence. Approach: Created a new array with double the size of the original array and filled the first half with the original elements, then copied the same elements again into the second half. Key Learning: ✔️ Practicing array construction and indexing ✔️ Understanding how to manipulate array sizes ✔️ Writing clean logic for simple transformation problems If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Arrays #ProblemSolving #Consistency 

🚀 Day 32 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Sliding Window Technique 🧩 Problem Solved: Longest Substring Without Repeating Characters Problem: Given a string, find the length of the longest substring without repeating characters. Approach: Used a sliding window technique with two pointers and a hash array to track the last occurrence of characters. Whenever a repeating character appeared within the current window, adjusted the left pointer to maintain a substring with unique characters. Key Learning: ✔️ Applying sliding window for substring problems ✔️ Using hashing for constant-time character tracking ✔️ Optimizing from brute-force to O(n) time complexity If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency

🚀 Day 33 / 180 – DSA with Java 🚀 📘 Topic Covered: Arrays & Index Manipulation 🧩 Problem Solved: Shuffle the Array Problem: Given an array in the form [x1, x2, ..., xn, y1, y2, ..., yn], rearrange it to [x1, y1, x2, y2, ..., xn, yn]. Approach: Used two pointers to track elements from the first and second halves of the array, then alternately placed them into a new array to achieve the required shuffle pattern. Key Learning: ✔️ Managing multiple pointers in array problems ✔️ Practicing index-based rearrangement ✔️ Maintaining correct ordering while constructing a new array If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Arrays #ProblemSolving #Consistency

Day 44 of #100DaysOfLeetCode 💻✅ Solved Very Simple #169. Majority Element problem in Java. Approach: • Sorted the given array using Arrays.sort() • Observed that the majority element appears more than n/2 times • After sorting, the majority element will always be present at index n/2 • Returned the element at nums[n/2] Performance: ✓ Runtime: 7 ms (Beats 42.86% submissions) ✓ Memory: 55.96 MB (Beats 16.21% submissions) Key Learning: ✓ Understood how sorting can help identify the majority element ✓ Learned the property that the majority element always occupies the middle position after sorting ✓ Practiced array manipulation and problem solving in Java Learning one problem every single day 🚀 #Java #LeetCode #DSA #Arrays #ProblemSolving #CodingJourney #100DaysOfCode

🚀 Day 29 / 180 – DSA with Java 🚀 📘 Topic Covered: Arrays & Two-Pointer Technique 🧩 Problem Solved: Container With Most Water Problem: Given an array where each element represents the height of a vertical line, find two lines that together with the x-axis form a container that holds the maximum amount of water. Approach: Used a two-pointer strategy starting from both ends of the array. Calculated the water area using the shorter height and the distance between pointers, then moved the pointer with the smaller height to try finding a better container. Key Learning: ✔️ Efficient use of two-pointer technique ✔️ Understanding how pointer movement impacts optimization ✔️ Reducing brute-force O(n²) solutions to O(n) If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Arrays #ProblemSolving #Consistency

🚀 DSA Learning Journey | Day 2 | Java Solved “Next Permutation.” 💡 Key Idea: Find the first decreasing element from the right, swap it with the next greater element, then reverse the remaining suffix to get the next lexicographical permutation. ⚙ Implementation • Language: Java • Time Complexity: O(n) • Space Complexity: O(1) 📚 Learning how permutation logic works and how reversing the suffix ensures the next smallest arrangement. #Java #DSA #LeetCode #ProblemSolving #JavaDeveloper #Algorithms

✨ DSA in Java – Day 83 🚀 Today I solved an interesting problem on Binary Trees: 👉 Sum of Root to Leaf Binary Numbers 🌱 What I Learned: How to traverse a binary tree using DFS (Depth First Search) Building numbers along the path using: ➤ current = current * 2 + node.val Identifying leaf nodes and calculating final values Improving recursion understanding in tree problems 💡 Approach: Start from root with value 0 At each node, update the current number If it's a leaf node → add it to the final sum Traverse left and right recursively 📌 Key Insight: Binary tree problems become easier when you think of them as path-based problems rather than node-based problems. 💻 Consistency is the key! Day by day, step by step, getting stronger in DSA 💪 #DSA #Java #BinaryTree #CodingJourney #LeetCode #100DaysOfCode #WomenInTech #Consistency

🚀 Day 27 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Reverse Traversal 🧩 Problem Solved: Length of Last Word Problem: Given a string containing words separated by spaces, find the length of the last word. Approach: Started traversing the string from the end, skipped trailing spaces first, and then counted characters until encountering another space or reaching the beginning of the string. Key Learning: ✔️ Efficient reverse traversal in strings ✔️ Handling edge cases like trailing spaces ✔️ Writing simple yet optimized string logic If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency

🚀 Day 31 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Substring Search 🧩 Problem Solved: Find the Index of the First Occurrence in a String Problem: Given two strings haystack and needle, return the index of the first occurrence of needle in haystack. If it is not present, return -1. Approach: Traversed the main string and checked potential starting positions where the first character matched. Then compared the substring of the same length as the target string to verify a complete match. Key Learning: ✔️ Understanding substring search logic ✔️ Optimizing comparisons by checking the first character first ✔️ Practicing careful boundary handling in string traversal If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency