Median of Two Sorted Arrays: Binary Search Approach

Day 58/100 | #100DaysOfDSA 🔄🔍 Today’s problem: Search in Rotated Sorted Array A twist on Binary Search with a rotated array. Key idea: Even though the array is rotated, one half is always sorted. Approach: • Use binary search • Find mid element • Check which half is sorted (left or right) • Decide if target lies in the sorted half • Narrow the search accordingly Why it works: At every step, we eliminate half of the search space just like standard binary search. Time Complexity: O(log n) Space Complexity: O(1) Big takeaway: Understanding the structure of the problem helps adapt classic algorithms like binary search. Rotation doesn’t break order — it just shifts it. 🔥 Day 58 done. #100DaysOfCode #LeetCode #DSA #Algorithms #BinarySearch #Arrays #Java #CodingJourney #ProblemSolving #InterviewPrep #TechCommunity

Day 57/100 | #100DaysOfDSA ⛰️🔍 Today’s problem: Peak Index in a Mountain Array A perfect use-case of Binary Search on a pattern. Key observation: The array increases → reaches a peak → then decreases. Approach: • Use binary search on the index • Compare mid with mid + 1 • If arr[mid] > arr[mid + 1] → we are on the decreasing side → move left • Else → we are on the increasing side → move right This guarantees we always move toward the peak. Time Complexity: O(log n) Space Complexity: O(1) Big takeaway: Binary search isn’t just for sorted arrays — it works on patterns too. Recognizing these patterns is a game changer. 🔥 Day 57 done. #100DaysOfCode #LeetCode #DSA #Algorithms #BinarySearch #Arrays #Java #CodingJourney #ProblemSolving #InterviewPrep #TechCommunity

Day 59/100 | #100DaysOfDSA 🔍⚡ Today’s problem: Single Element in a Sorted Array A clever Binary Search problem with a twist. Key observation: In a sorted array where every element appears twice except one, pairs follow a pattern. Before the single element: • First occurrence → even index • Second occurrence → odd index After the single element: • Pattern breaks Approach: • Use binary search • Check mid with its pair using index trick (mid ^ 1) • If nums[mid] == nums[mid ^ 1] → move right • Else → move left This helps pinpoint where the pattern breaks. Time Complexity: O(log n) Space Complexity: O(1) Big takeaway: Bit manipulation + pattern observation can simplify binary search problems significantly. Small tricks → big optimizations. 🔥 Day 59 done. #100DaysOfCode #LeetCode #DSA #Algorithms #BinarySearch #BitManipulation #Arrays #Java #CodingJourney #ProblemSolving #InterviewPrep #TechCommunity

Day 68 of My DSA Journey Today’s problem: Symmetric Tree 🌳 Problem Statement Given a binary tree, check whether it is a mirror of itself (symmetric around its center). Key Insight A tree is symmetric if: Left subtree is a mirror of the right subtree Compare nodes in a cross manner: Left → Left with Right → Right Left → Right with Right → Left 🧠 Approach Use recursion to compare two nodes at a time Base cases: If both nodes are null → symmetric If one is null → not symmetric Check: Values are equal Outer and inner pairs match ⚡ Complexity Time: O(n) Space: O(h) (recursion stack) ✨ What I Learned This problem improved my understanding of recursion and how to think in terms of mirror structures instead of normal traversal. Consistency is the key 🔑 — one problem at a time! #DSA #Java #BinaryTree #CodingJourney #100DaysOfCode

🚀 #100DaysOfCode | Day 47 🔍 Solved: Find Minimum in Rotated Sorted Array Today I explored another interesting variation of Binary Search. Instead of searching for a target, the goal was to find the minimum element in a rotated sorted array. 💡 Key Insight: By comparing the middle element with the last element, we can determine which half contains the minimum value. Approach: ✔ Used Binary Search to achieve O(log n) time complexity ✔ Compared mid with end to identify the unsorted portion ✔ Narrowed down the search space efficiently What I Learned: This problem helped me understand how binary search can be applied beyond simple searching—especially in rotated and partially sorted arrays. #Java #DSA #LeetCode #BinarySearch #CodingJourney #ProblemSolving #TechSkills

Day 62/100 | #100DaysOfDSA 🧩🚀 Today’s problem: Combination Sum Classic backtracking problem. Problem idea: Find all unique combinations where numbers sum up to a target. Each number can be used unlimited times. Key idea: Use backtracking (choose → explore → backtrack). Why? • We need to explore all possible combinations • Stop when sum exceeds target • Add result when sum == target How it works: • Pick a number • Stay on same index (reuse allowed) • Move forward when skipping • Backtrack to try other paths Time Complexity: Exponential (depends on combinations) Space Complexity: O(target) recursion depth Big takeaway: Backtracking is all about exploring choices and undoing them efficiently. This pattern is super important for recursion problems. 🔥 Day 62 done. #100DaysOfCode #LeetCode #DSA #Algorithms #Backtracking #Java #CodingJourney #ProblemSolving #InterviewPrep #TechCommunity

Day 9/ #100DaysOfCode Solved LeetCode 1848: Minimum Distance to the Target Element. Approach: The problem can be solved using a straightforward linear traversal. Iterate through the array and check for indices where the value equals the target. For each such index, compute the absolute difference between the current index and the given start index. Maintain a variable to track the minimum distance encountered during the traversal. Solution Insight: Initialize a variable with a large value (e.g., Integer.MAX_VALUE). Traverse the array once. Whenever the target element is found, update the minimum distance using Math.abs(i - start). Return the minimum value after the loop. Complexity: Time Complexity: O(n) Space Complexity: O(1) Result: 72/72 test cases passed with optimal runtime performance. This problem reinforces the importance of simple iteration and careful tracking of minimum values in array-based problems. #100DaysOfCode #LeetCode #DSA #Java #ProblemSolving #Algorithms

Day 60/100 | #100DaysOfDSA 🧩🚀 Today’s problem: Minimized Maximum of Products Distributed to Any Store Interesting use of binary search on answer. Problem idea: We need to distribute products to stores such that the maximum products any store gets is minimized. Key idea: Apply binary search on the answer (max products per store). Why? • If a maximum limit works → try smaller • If it doesn’t → increase the limit For each candidate value: • Check how many stores are required • If stores ≤ given n → valid distribution This way we efficiently find the minimum possible maximum. Time Complexity: O(n log m) Space Complexity: O(1) Big takeaway: Whenever you need to minimize the maximum (or maximize the minimum) → think Binary Search on Answer. These patterns are becoming clearer day by day. 🔥 Day 60 done. #100DaysOfCode #LeetCode #DSA #Algorithms #BinarySearch #Java #CodingJourney #ProblemSolving #InterviewPrep #TechCommunity

𝐃𝐚𝐲 𝟓𝟔 – 𝐃𝐒𝐀 𝐉𝐨𝐮𝐫𝐧𝐞𝐲 | 𝐀𝐫𝐫𝐚𝐲𝐬 🚀 Today’s problem focused on finding a peak element using binary search. 𝐏𝐫𝐨𝐛𝐥𝐞𝐦 𝐒𝐨𝐥𝐯𝐞𝐝 • Find Peak Element 𝐀𝐩𝐩𝐫𝐨𝐚𝐜𝐡 • Used binary search instead of linear scan • Compared the middle element with its next element Logic: • If nums[mid] > nums[mid + 1] → peak lies on the left side (including mid) • Else → peak lies on the right side • Continued until left == right 𝐊𝐞𝐲 𝐋𝐞𝐚𝐫𝐧𝐢𝐧𝐠𝐬 • Binary search can be applied on patterns, not just sorted arrays • A peak always exists due to problem constraints • Comparing adjacent elements helps determine direction • Reducing the search space is the key idea 𝐂𝐨𝐦𝐩𝐥𝐞𝐱𝐢𝐭𝐲 • Time: O(log n) • Space: O(1) 𝐓𝐚𝐤𝐞𝐚𝐰𝐚𝐲 Binary search is not about sorted arrays — it’s about eliminating half of the search space using logic. 56 days consistent 🚀 On to Day 57. #DSA #Arrays #BinarySearch #LeetCode #Java #ProblemSolving #DailyCoding #LearningInPublic #SoftwareDeveloper

🚀 Day 41 of #100DaysOfDSA (Java) Today I continued with Graphs (Part 2) and covered important concepts used in real interview problems. Topics covered: 🔹 Connected Components in Graphs 🔹 Cycle Detection in Undirected Graph (DFS) 🔹 Cycle Detection in Directed Graph (DFS) 🔹 Bipartite Graph 🔹 Topological Sorting (using DFS) Key takeaway: Graph problems are all about traversal + state tracking. Understanding how to use DFS with additional conditions (like parent tracking or recursion stack) is crucial for solving problems like cycle detection and topological sorting. Day 41 ✅ Strengthening concepts in one of the most important DSA topics. #DSA #Java #Graphs #DFS #TopologicalSort #ProblemSolving #100DaysOfCode #DeveloperJourney #LearningInPublic