Java LeetCode 205: Isomorphic Strings Solution

Day 68 of #100DaysOfLeetCode 💻✅ Solved #977. Squares of a Sorted Array problem in Java. Approach: • Traversed the array and squared each element • Used Arrays.sort() to sort the squared values • Returned the sorted array as the result Performance: ✓ Runtime: 10 ms (Beats 37.38% submissions) ✓ Memory: 47.98 MB (Beats 18.78% submissions) Key Learning: ✓ Practiced array transformation and sorting ✓ Learned how squaring affects order in sorted arrays ✓ Understood the importance of optimizing from O(n log n) to O(n) using two pointers Learning one problem every single day 🚀 #Java #LeetCode #DSA #Arrays #Sorting #ProblemSolving #CodingJourney #100DaysOfCode

Day 69 of #100DaysOfLeetCode 💻✅ Solved #349. Intersection of Two Arrays problem in Java. Approach: • Iterated through each element of the first array • Checked if the element exists in the second array • Used a temporary array to store intersection elements • Ensured no duplicates by checking already added elements • Copied the result into a final array of correct size Performance: ✓ Runtime: 4 ms (Beats 35.60%) ✓ Memory: 44.41 MB (Beats 96.71%) Key Learning: ✓ Practiced array traversal using nested loops ✓ Learned how to handle duplicates manually ✓ Improved understanding of set-like operations without using extra data structures Learning one problem every single day 🚀 #Java #LeetCode #DSA #Arrays #ProblemSolving #CodingJourney #100DaysOfCode

Day 82 of #100DaysOfLeetCode 💻✅ Solved #11. Container With Most Water problem in Java. Approach: • Used Two Pointer technique • Calculated area using min height and width • Moved pointer with smaller height inward • Tracked maximum area throughout Performance: ✓ Runtime: 5 ms (Beats 83.17% submissions) ✓ Memory: 77.35 MB (Beats 53.65% submissions) Key Learning: ✓ Mastered Two Pointer optimization technique ✓ Learned efficient area calculation strategy ✓ Improved decision-making for pointer movement Learning one problem every single day 🚀 #Java #LeetCode #DSA #TwoPointers #Arrays #ProblemSolving #CodingJourney #100DaysOfCode

Day 63 of #100DaysOfLeetCode 💻✅ Solved #2085. Count Common Words With One Occurrence problem in Java. Approach: • Iterated through each word in the first array • Avoided duplicate checks by ensuring each word is processed only once • Counted occurrences of the current word in both arrays • If the word appears exactly once in both arrays, incremented the result • Returned the final count Performance: ✓ Runtime: 88 ms (Beats 7.45% submissions) ✓ Memory: 46.06 MB (Beats 93.07% submissions) Key Learning: ✓ Practiced handling duplicates and frequency counting ✓ Improved understanding of string comparison in arrays ✓ Learned importance of optimizing nested loop solutions Learning one problem every single day 🚀 #Java #LeetCode #DSA #Strings #Arrays #ProblemSolving #CodingJourney #100DaysOfCode

Day 76 of #100DaysOfLeetCode 💻✅ Solved #33. Search in Rotated Sorted Array problem in Java. Approach: • Applied Binary Search on rotated array • Checked which half is sorted at each step • Reduced search space based on target position Performance: ✓ Runtime: 0 ms (Beats 100.00% submissions) 🚀 ✓ Memory: 43.80 MB (Beats 70.96% submissions) Key Learning: ✓ Mastered searching in rotated sorted arrays ✓ Improved Binary Search decision-making ✓ Learned efficient handling of edge cases Learning one problem every single day 🚀 #Java #LeetCode #DSA #BinarySearch #Arrays #ProblemSolving #CodingJourney #100DaysOfCode

Day 66 of #100DaysOfLeetCode 💻✅ Solved #3427. Sum of Variable Length Subarrays problem in Java. Approach: • Iterated through each index of the array • Determined the starting index using i - nums[i] • Ensured the start index does not go below 0 • Calculated sum of elements from start to current index i • Added each subarray sum to the total Performance: ✓ Runtime: 1 ms (Beats 99.90% submissions) ✓ Memory: 45.22 MB (Beats 56.30% submissions) Key Learning: ✓ Practiced handling variable-length subarrays ✓ Improved understanding of index-based range calculations ✓ Strengthened nested loop logic for array problems Learning one problem every single day 🚀 #Java #LeetCode #DSA #Arrays #PrefixSum #ProblemSolving #CodingJourney #100DaysOfCode

🚀 Day 39/100 Today’s problem: Reverse String II 🔹 Worked on reversing characters in a string based on a given value k🔹 Used char[] and two-pointer approach for efficient swapping 💡 What I Learned:✔ How to handle string manipulation using arrays in Java✔ Importance of index control while working with loops✔ How to solve problems step-by-step instead of reversing the whole string directly✔ Improved logic building for partial reversal problems 💡 Key Insight:Instead of reversing the entire string, we reverse only specific parts (every 2k characters), which requires careful indexing. Consistency is slowly turning into confidence 💪 #Day39 #Java #DSA #CodingJourney #LeetCode #ProblemSolving #100DaysOfCode

Solved LeetCode 17 – Letter Combinations of a Phone Number using backtracking in Java. Approach: Mapped each digit (2–9) to its corresponding characters using a simple array for O(1) access. Then used backtracking to build combinations digit by digit. For every digit: Pick each possible character Append → explore next digit → backtrack Key idea: Treat it like a tree of choices, where each level represents a digit and branches represent possible letters. Key learnings: Backtracking = build → explore → undo StringBuilder helps avoid unnecessary string creation Problems like this are about systematic exploration of choices Time Complexity: O(4^n * n) Space Complexity: O(n) recursion stack + output Consistent DSA practice is strengthening pattern recognition day by day. #Java #DSA #Backtracking #LeetCode #CodingInterview #SoftwareEngineering

Day 61 of #100DaysOfLeetCode 💻✅ Solved #541. Reverse String II problem in Java. Approach: • Converted the string into a character array • Traversed the array in steps of 2k • For every segment, reversed the first k characters • Used two-pointer technique to perform in-place reversal • Math.min() to handle cases where remaining characters are less than k Performance: ✓ Runtime: 2 ms (Beats 16.04% submissions) ✓ Memory: 44.80 MB (Beats 73.53% submissions) Key Learning: ✓ Practiced handling strings with fixed pattern intervals ✓ Improved control over indexing and boundaries ✓ Strengthened in-place modification techniques Learning one problem every single day 🚀 #Java #LeetCode #DSA #Strings #TwoPointers #ProblemSolving #CodingJourney #100DaysOfCode

🚀 Day 41/180 | #180DaysOfCode 📍 LeetCode | 💻 Java Solved: 3427. Sum of Variable Length Subarrays Used a nested loop approach to calculate subarray sums for each index by dynamically determining the starting point using max(0, i - nums[i]). ⏱️ Time Complexity: O(n²) 📦 Space Complexity: O(1) Strengthening understanding of subarray problems and index-based range calculations. 💪 Consistency continues 🚀 #DSA #LeetCode #Java #CodingJourney #Consistency