Construct Minimum Bitwise Array II with LeetCode

📅 Day 80 of #100DaysOfLeetCode 🧩 Problem: 3819. Rotate Non-Negative Elements Difficulty: Medium 💡 Key Insight Negative elements must act like fixed blockers. So instead of rotating the entire array, we: Extract only non-negative elements Rotate that extracted list Put them back only into non-negative positions This avoids disturbing any negative indices 🚫. 🛠️ Approach Count how many non-negative elements exist (pc). Reduce k using k % pc to avoid unnecessary rotations. Store all non-negative elements in a temporary array. Perform left rotation using the reverse array technique: Reverse first k elements Reverse remaining elements Reverse the whole array Traverse the original array and replace only non-negative positions with rotated values. ⏱️ Complexity Time: O(n) Space: O(pc) #LeetCode #Java #ProblemSolving #CodingChallenge #100DaysOfCode #DSA #LearningEveryday

🔥 Day 82 of #100DaysOfLeetCode ✅ Problem: Number of Longest Increasing Subsequence ✅ Difficulty: Medium 💡 Key Insight: Instead of tracking only the LIS length, we also maintain the number of ways each LIS can be formed. For every element, we check all previous smaller elements and update both length and count dynamically. 🛠 Approach: Use two arrays: dp[i] → Length of LIS ending at index i cnt[i] → Number of LIS ending at index i If a longer subsequence is found → update length and copy count. If another subsequence of the same length is found → add the counts. Finally, sum counts for indices having the maximum LIS length. ⏱ Complexity: Time: O(n²) Space: O(n) #LeetCode #Java #ProblemSolving #CodingChallenge #100DaysOfCode #DSA #LearningEveryday

Day 3 of Daily DSA 🚀 Solved LeetCode 1: Two Sum Approach: Used a HashMap to store numbers with their indices. For each element, checked if the complement (target - current) already exists. Complexity: • Time: O(n) • Space: O(n) Performance: Runtime: 2 ms (Beats 99.15%) Memory: 47.34 MB Focusing on writing clean and efficient solutions before over-optimizing. Consistency > Intensity 💯 #DSA #LeetCode #Java #ProblemSolving #Consistency

Day 7 of Daily DSA 🚀 Solved LeetCode 167: Two Sum II – Input Array Is Sorted Approach: Used the two-pointer technique leveraging the sorted nature of the array. Moved pointers inward based on the comparison with the target to find the answer in one pass. Complexity: • Time: O(n) • Space: O(1) (constant extra space) LeetCode Stats: • Runtime: 2 ms (Beats 96.10%) • Memory: 48.54 MB (Beats 38.87%) This problem highlights how understanding input constraints can turn a brute-force solution into an optimal one. #DSA #LeetCode #Java #TwoPointers #ProblemSolving #Consistency

Day 60/100 – LeetCode Challenge ✅ Problem: #67 Add Binary Difficulty: Easy Language: Java Approach: Reverse Iteration with Carry Time Complexity: O(max(n, m)) Space Complexity: O(max(n, m)) Key Insight: Binary addition follows same rules as decimal: Sum bits + carry Result bit = sum % 2 New carry = sum / 2 Solution Brief: Iterated from rightmost bits of both strings. Tracked carry and built result from right to left using StringBuilder. Reversed final string for correct order. #LeetCode #Day60 #100DaysOfCode #Binary #Java #Algorithm #CodingChallenge #ProblemSolving #AddBinary #EasyProblem #StringManipulation #BitManipulation #DSA

🚀 Day 4 of #100DaysOfCode Solved Single Element in a Sorted Array on LeetCode using Binary Search ⚡ 🧠 Key insight: In a sorted array where every element appears twice except one, index parity (even/odd) helps decide which half to search. ⚙️ Approach: 🔹Apply binary search 🔹Compare mid with its adjacent element 🔹Use index parity to move left or right 🔹Narrow down until the single element is found ⏱️ Time Complexity: O(log n) 📦 Space Complexity: O(1) #100DaysOfCode #LeetCode #DSA #BinarySearch #Java #ProblemSolving #LearningInPublic #CodingJourney

Day 10 of Daily DSA 🚀 Solved LeetCode 190: Reverse Bits ✅ 🔍 Approach: Worked with the 32-bit representation of the given integer: • Converted the number into a fixed 32-bit binary string • Used a two-pointer technique to reverse the bits • Converted the reversed binary back to an unsigned integer This approach keeps the logic simple while ensuring correctness for signed integers. ⏱ Complexity: • Time: O(32) = O(1) (constant time) • Space: O(32) = O(1) 📊 LeetCode Stats: • Runtime: 9 ms • Memory: 43.46 MB A good reminder that clarity matters more than micro-optimizations when learning bit manipulation. #DSA #LeetCode #Java #BitManipulation #ProblemSolving #DailyCoding #Consistency

🔹 Day 85 – #100DaysOfLeetCode Problem: 3010. Divide an Array Into Subarrays With Minimum Cost I Difficulty: Easy Key Insight: The cost of a subarray depends only on its first element. Since the first subarray always starts at index 0, the problem reduces to selecting the two smallest possible starting elements from the remaining array. Approach: Fix the first subarray cost as nums[0] Find the smallest and second smallest values in nums[1…n-1] Add them to get the minimum total cost Time Complexity: O(n) Space Complexity: O(1) #LeetCode #Java #ProblemSolving #CodingChallenge #100DaysOfCode #DSA #LearningEveryday

🧠 Day 76 of #100DaysOfLeetCode 📌 Problem: Combination Sum II 📊 Difficulty: Medium 💡 Key Insight: Sorting the array helps handle duplicates. While backtracking, duplicates are skipped only in the “not pick” path to ensure unique combinations. 🛠️ Approach: Sort the candidates array Use backtracking to explore combinations Each number can be used once → move to index + 1 Skip duplicate elements to avoid repeated combinations ⏱️ Complexity: Time: O(2^n) Space: O(n) #LeetCode #Java #ProblemSolving #CodingChallenge #100DaysOfCode #DSA #LearningEveryday

Day 9 of #100DaysOfLeetCode 💻✅ Solved Valid Parentheses problem in Java using Stack. Approach: Used a stack to store opening brackets Pushed opening brackets ( { [ into the stack When a closing bracket appeared, checked if it matches the latest opening bracket Returned false if mismatch or stack becomes empty unexpectedly Finally checked if stack is empty to confirm valid parentheses Performance: ✓ Runtime: 3 ms (Beats 87.85%) ✓ Memory: 43.29 MB (Beats 70.02%) Key Learning: ✓ Strengthened understanding of Stack data structure ✓ Improved bracket matching and string traversal logic Learning and improving one problem every single day 🚀 #Java #LeetCode #Stack #ProblemSolving #CodingJourney #100DaysOfCode #DSA