Java Arrays Sorting and Swapping for DSA

🚀 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 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 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 17 / 180 – DSA with Java 🚀 📘 Topic Covered: Arrays & Reversal Algorithm 🧩 Problem Solved: Rotate Array Problem: Rotate an array to the right by k steps, modifying it in-place without using extra space. Approach: Used the reversal algorithm: 1️⃣ Reversed the entire array 2️⃣ Reversed the first k elements 3️⃣ Reversed the remaining elements This efficiently achieved rotation in O(n) time with O(1) extra space. Key Learning: ✔️ Using reversal technique for array manipulation ✔️ Breaking complex operations into smaller steps ✔️ Writing optimized in-place solutions If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Arrays #ProblemSolving #Consistency 

🚀 Day 18 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Carry-Based Addition 🧩 Problem Solved: Add Binary Problem: Given two binary strings, return their sum as a binary string. Approach: Traversed both strings from right to left, added corresponding digits along with carry, and built the result step by step. Used a string builder and reversed the final result to get the correct order. Key Learning: ✔️ Handling carry logic in string-based arithmetic ✔️ Simulating manual binary addition programmatically ✔️ Managing different string lengths efficiently If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency

🚀 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 14 / 180 – DSA with Java 🚀 📘 Topic Covered: Arrays & Sorted-Rotation Logic 🧩 Problem Solved: Check if Array is Sorted and Rotated Problem: Determine whether a given array is sorted in non-decreasing order and then possibly rotated. Approach: Traversed the array and counted how many times the order decreases (where the current element is smaller than the previous one). If the count of such “break points” is at most one (including the circular check between last and first elements), the array satisfies the condition. Key Learning: ✔️ Understanding sorted array properties ✔️ Handling circular array comparisons ✔️ Solving rotation-based problems efficiently in O(n) time If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Arrays #ProblemSolving #Consistency

🚀 Day 13 / 180 – DSA with Java 🚀 📘 Topic Covered: Loops & Conditional Logic 🧩 Problem Solved: FizzBuzz Problem: For numbers from 1 to n, return: • “Fizz” if divisible by 3 • “Buzz” if divisible by 5 • “FizzBuzz” if divisible by both • Otherwise, return the number itself Approach: Iterated from 1 to n, checked divisibility conditions, built the appropriate string dynamically, and stored the result in a list. Key Learning: ✔️ Strengthening control flow fundamentals ✔️ Handling multiple conditions cleanly ✔️ Writing simple yet structured logic If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #ProblemSolving #Consistency 

🚀 Day 19 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Greedy Traversal 🧩 Problem Solved: Largest Odd Number in a String Problem: Given a numeric string, return the largest-valued odd-numbered substring. If no odd digit exists, return an empty string. Approach: Traversed the string from right to left to find the first odd digit. Once found, returned the substring from the start up to that index to ensure the largest possible odd number. Key Learning: ✔️ Observing patterns to reduce unnecessary computation ✔️ Efficient right-to-left traversal ✔️ Applying greedy thinking in string problems If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency

🚀 Day 28 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Sliding Window 🧩 Problem Solved: Divisor Substrings Problem: Given an integer num and an integer k, find the number of substrings of length k from the digits of num such that the substring value divides num. Approach: Converted the number to a string and used a sliding window of size k to extract substrings. Each substring was converted back to an integer and checked whether it divides the original number. Key Learning: ✔️ Applying sliding window technique on strings ✔️ Converting between numeric and string representations ✔️ Handling edge cases like division by zero If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency