Java LeetCode Problem 1: Find First Occurrence in String

🚀 Day 98 - #100DaysOfCode Today’s problem was all about string comparison and operations simulation in Java. 💡 Problem Insight: Given a list of operations like "++X", "X++", "--X", "X--", we need to compute the final value of X after performing all operations. ⚠️ One key learning today: In Java, always use .equals() for string comparison instead of ==. Using == compares references, not actual content — a very common mistake! 🧠 Approach: Initialize x = 0 Traverse through each operation Increment or decrement based on the operation string 📌 What I Improved Today: Better understanding of string handling in Java Avoiding common pitfalls in comparisons Writing cleaner conditional logic #Java #CodingJourney #LeetCode #100DaysOfCode #ProblemSolving #Consistency

LeetCode Problem || Find Unique Binary String (1980)🚀 Today I solved the problem "Find Unique Binary String" using Java. 🔹 Problem: We are given an array of n binary strings, each of length n. The goal is to return a binary string of length n that does not exist in the array. 🔹 Approach (Diagonal Flip Technique): The idea is simple but powerful: Traverse the array using index i. Look at the i-th character of the i-th string (nums[i][i]). Flip the bit (0 → 1, 1 → 0). Append it to a result string. 💡 Time Complexity: O(n) Practicing problems like this strengthens logical thinking and problem-solving skills. #LeetCode #Java #CodingPractice #ProblemSolving #DSA

Day 34 of #100DaysOfLeetCode 💻✅ Solved #110. Balanced Binary Tree on LeetCode using Java. Approach: • Used a bottom-up recursive approach to calculate height • Returned -1 immediately if any subtree is unbalanced • Compared left and right subtree heights at each node • Checked if the height difference is greater than 1 • Stopped early to optimize unnecessary computations Performance: ✓ Runtime: 0 ms (Beats 100.00% submissions) ✓ Memory: 45.33 MB (Beats 95.41% submissions) Key Learning: ✓ Understood how to combine height calculation with balance checking ✓ Learned early termination technique in recursion ✓ Improved problem-solving for tree-based recursive problems Learning one problem every single day 🚀 #Java #LeetCode #DSA #BinaryTree #Recursion #TreeProblems #ProblemSolving #CodingJourney #100DaysOfCode

Today I solved “Fibonacci Number” on LeetCode using Java. 💡 Problem Summary The Fibonacci sequence is defined as: F(0) = 0 F(1) = 1 F(n) = F(n-1) + F(n-2) We need to compute F(n). 🧠 Approach I Used (Iterative Optimization) Instead of recursion (which is slow and redundant), I used an iterative approach: Maintain two variables → previous two values Keep updating them in a loop Build the answer step by step ⚙️ Why Not Recursion? Recursion leads to repeated calculations Time complexity becomes O(2ⁿ) ❌ Iterative solution reduces it to O(n) ✅ 📊 Complexity Analysis ⏱️ Time Complexity: O(n) 📦 Space Complexity: O(1) ⚡ Result ✅ Accepted ⚡ Runtime: 0 ms (Beats 100%) 📚 Key Learning Always try to optimize recursion → iteration Use variables smartly to reduce space Even simple problems teach important optimization patterns Slowly building strong fundamentals, one problem at a time 💯 Day 15 done. Let’s keep the streak alive 🔥 #DSA #LeetCode #Java #100DaysOfCode #Algorithms #ProblemSolving #CodingJourney #Consistency #LearningInPublic

Day 3/50 | #50DaysOfCode 📍 Platform: LeetCode 💻 Language: Java ✅ 1768. Merge Strings Alternately (Easy) Today’s problem focused on string manipulation and efficient merging techniques. It helped reinforce my understanding of string traversal and handling different string lengths. 🔎 Approach: Use a loop to iterate through both strings simultaneously Append characters alternately from word1 and word2 Check if one string is longer than the other Append the remaining characters at the end Return the final merged string 📌 Example: Input: word1 = "abc", word2 = "pqr" Output: "apbqcr" This problem improved my understanding of string handling, indexing, and building efficient logic using Java. #DSA #LeetCode #Java #CodingJourney #ProblemSolving #Consistency #LearningJourney #50DaysOfCode #LinkedIn

Day 3/50 | #50DaysOfCode 📍 Platform: LeetCode 💻 Language: Java ✅ 977. Squares of a Sorted Array (Easy) Today’s problem focused on array manipulation and sorting logic. It helped me understand how negative numbers affect order after squaring and how to maintain sorted order efficiently. 🔎 Approach: Traverse the array and calculate the square of each element Store the squared values in a new array Sort the new array in non-decreasing order Return the sorted squared array 📌 Example: Input: nums = [-4, -1, 0, 3, 10] Output: [0, 1, 9, 16, 100] This problem strengthened my understanding of arrays, sorting, and handling negative values in Java. #DSA #LeetCode #Java #CodingJourney #ProblemSolving #Consistency #LearningJourney #50DaysOfCode #LinkedIn

Day 31 of #100DaysOfLeetCode 💻✅ Solved #94. Binary Tree Inorder Traversal on LeetCode using Java. Approach: • Used recursion to perform inorder traversal • Followed Left → Root → Right order strictly • Traversed left subtree first before processing current node • Stored node values in a list during traversal • Returned the final list after complete traversal Performance: ✓ Runtime: 0 ms (Beats 100.00% submissions) ✓ Memory: 42.76 MB (Beats 98.30% submissions) Key Learning: ✓ Strengthened understanding of tree traversal patterns ✓ Improved clarity on recursion stack behavior ✓ Reinforced difference between preorder, inorder, and postorder traversal Learning one problem every single day 🚀 #Java #LeetCode #DSA #BinaryTree #Recursion #TreeTraversal #ProblemSolving #CodingJourney #100DaysOfCode

Day 33 of #100DaysOfLeetCode 💻✅ Solved #145. Binary Tree Postorder Traversal on LeetCode using Java. Approach: • Used recursion to perform postorder traversal • Followed Left → Right → Root order strictly • Traversed left subtree first • Then traversed right subtree • Added node value after visiting both subtrees Performance: ✓ Runtime: 0 ms (Beats 100.00% submissions) ✓ Memory: 43.12 MB (Beats 71.37% submissions) Key Learning: ✓ Clearly understood difference between preorder, inorder, and postorder ✓ Strengthened recursive tree traversal concepts ✓ Improved confidence in handling binary tree problems Learning one problem every single day 🚀 #Java #LeetCode #DSA #BinaryTree #Recursion #TreeTraversal #ProblemSolving #CodingJourney #100DaysOfCode

🚀 DSA in Java – Day 76 ✅ Today I solved the “Check if Binary String Has at Most One Segment of Ones” problem on LeetCode. 💡 Problem Idea: Given a binary string, we need to check whether there is at most one continuous segment of '1's in the string. 🧠 Approach: Traverse the string using a loop. Count how many segments of '1' appear. If the count becomes greater than 1, return false. Otherwise return true. ⚡ Key Concepts Practiced: String traversal While loop Character comparison Logical conditions Consistency in solving problems every day is helping me strengthen my problem-solving and logical thinking skills in Java. #DSA #Java #LeetCode #ProblemSolving #CodingJourney #WomenInTech #100DaysOfCode

Day 32 of #100DaysOfLeetCode 💻✅ Solved #144. Binary Tree Preorder Traversal on LeetCode using Java. Approach: • Used recursion to perform preorder traversal • Followed Root → Left → Right order strictly • Added node value before traversing subtrees • Traversed left subtree first, then right subtree • Stored values in a list during traversal Performance: ✓ Runtime: 0 ms (Beats 100.00% submissions) ✓ Memory: 42.83 MB (Beats 96.77% submissions) Key Learning: ✓ Strengthened understanding of preorder traversal pattern ✓ Clearly differentiated preorder from inorder traversal ✓ Improved recursive tree traversal implementation skills Learning one problem every single day 🚀 #Java #LeetCode #DSA #BinaryTree #Recursion #TreeTraversal #ProblemSolving #CodingJourney #100DaysOfCode