Solved Basic Calculator problem on LeetCode using C++ and stack.

📅 Day 35 of #100DaysOfCode Problem: Search in Rotated Sorted Array II (LeetCode 81) Approach: 1️⃣ First, handled duplicates by skipping consecutive equal elements from both ends to avoid confusion while finding the rotation point. 2️⃣ Used a modified binary search to find the pivot (the smallest element’s index) — this separates the rotated parts of the array. 3️⃣ Performed binary search on both halves — before and after the pivot — to check where the target lies. 4️⃣ Returned true if found in either part, else false. #100DaysOfCode #LeetCode #BinarySearch #RotatedArray #ProblemSolving #Algorithms #DSA #Cplusplus #CodingChallenge #Programming #DeveloperLife #CodeNewbie #DailyDSA #TechCommunity #KeepLearning #SoftwareEngineering #LearningInPublic #Motivation

📅 Day 32 of #100DaysOfCode Problem: Design HashSet (LeetCode 705) Approach: 1️⃣ Used a boolean vector of fixed size (1,000,001) to represent presence or absence of elements directly by index. 2️⃣ add(key) marks the key as true, meaning it’s present in the set. 3️⃣ remove(key) simply resets the value to false. 4️⃣ contains(key) checks presence in O(1) time using direct indexing — super efficient and clean! #100DaysOfCode #LeetCode #DSA #ProblemSolving #Cplusplus #CodingChallenge #HashSet #DataStructures #Algorithms #CodeNewbie #Programming #DeveloperLife #SoftwareEngineering #LearningInPublic #TechCommunity #KeepLearning #CodingJourney #Motivation #Efficiency

📅 Day 48 of #100DaysOfCode Problem: Search in Rotated Sorted Array II (LeetCode 81) Approach: 1️⃣ First, used a pivot function to find the smallest element’s index, skipping duplicate values on both sides. 2️⃣ Once the pivot was found, split the array into two sorted parts. 3️⃣ Applied normal binary search on both halves to find the target. 4️⃣ Combined both steps to handle rotations and duplicates efficiently. #100DaysOfCode #LeetCode #DSA #ProblemSolving #BinarySearch #Cplusplus #CodingChallenge #Algorithms #Programming #DeveloperLife #CodeNewbie #SoftwareEngineering #CodingJourney #DailyDSA #KeepLearning #TechCommunity #GrowthMindset #Motivation

📅 Day 41 of #100DaysOfCode Problem: Merge k Sorted Lists (LeetCode 23) This one was all about optimization and clean recursion. Instead of merging lists one by one, I used a divide and conquer approach merge them in pairs, just like merge sort. Approach: 1️⃣ If there’s only one list, return it - base case. 2️⃣ Split the range of lists into two halves using recursion. 3️⃣ Merge both halves using a helper function that merges two sorted lists. 4️⃣ Keep dividing until everything is combined into one sorted list. #100DaysOfCode #LeetCode #DSA #Cplusplus #ProblemSolving #DivideAndConquer #Recursion #CodingChallenge #Algorithms #Programming #CodeNewbie #DeveloperLife #LearningInPublic #KeepLearning #SoftwareEngineering #TechCommunity #DailyDSA #GrowthMindset #Motivation

📅 Day 28 of #100DaysOfCode 🚀 Problem: 49. Group Anagrams (LeetCode) Approach: -> For each string, sort its characters — the sorted version acts as a unique key for its anagram group. -> Store all words with the same sorted key inside a hash map (unordered_map<string, vector<string>>). -> After processing all words, collect all grouped values from the map into a result vector. ->This leverages hashing + sorting for efficient grouping — O(n * k log k) where k is average string length. #100DaysOfCode #LeetCode #DSA #ProblemSolving #Cplusplus #CodingChallenge #Algorithms #DataStructures #Hashing #StringManipulation #CodingCommunity #Programming #DeveloperLife #LearnToCode #TechCommunity #DailyDSA #CodeNewbie #SoftwareEngineering #CodingJourney #Consistency #KeepLearning #LearningInPublic #GrowthMindset #Motivation

💡 Day 84 of My LeetCode Journey – Problem 1614: Maximum Nesting Depth of Parentheses Today’s problem tested my understanding of stack concepts and string traversal — determining how deeply parentheses are nested in a given string. 🧠 Concept: The idea is simple yet elegant: Traverse the string character by character. Use a counter to track the number of open parentheses (. Update the maximum depth whenever the count increases. Decrease the counter when a closing parenthesis ) appears. Example: "(1+(2*3)+((8)/4))+1" → Maximum depth = 3 ✅ Key Takeaways: Strengthened understanding of parentheses matching and depth counting. Improved ability to simulate stack behavior without extra space. Reinforced skills in clean logic implementation and iteration control. Small yet powerful problems like this sharpen clarity, precision, and logical thinking 🧩 #LeetCode #ProblemSolving #100DaysOfCode #DSA #CodingChallenge #Programming #LogicBuilding #Cplusplus #DailyCoding #LearningEveryday

📅 Day 47 of #100DaysOfCode Problem: Combination Sum II (LeetCode 40) Approach: 1️⃣ Sorted the array to handle duplicates easily. 2️⃣ Used recursion to explore each number — either include it or skip it. 3️⃣ Reduced the target as I added elements, and when the target hit 0, that path became a valid combination. 4️⃣ Skipped duplicates using a simple check: if (i > idx && candidates[i] == candidates[i-1]) continue. #100DaysOfCode #LeetCode #DSA #ProblemSolving #Backtracking #Recursion #Cplusplus #CodingChallenge #Algorithms #Programming #DeveloperLife #CodeNewbie #SoftwareEngineering #DailyDSA #CodingJourney #KeepLearning #TechCommunity #Motivation #GrowthMindset

📅 Day 36 of #100DaysOfCode Today’s challenge was one of the most interesting and tricky recursion problems! Problem: Regular Expression Matching (LeetCode #10) 🔍 Approach: The goal is to determine if a given string text matches a pattern that includes: . → Matches any single character * → Matches zero or more occurrences of the preceding element 1️⃣ Used recursion to check character-by-character matches. 2️⃣ For each step: Checked if the current characters match (text[0] == pattern[0] or pattern[0] == '.'). If the next pattern character is *, explored two possibilities: Skip * and the previous character (zero occurrence). Use * to match one or more occurrences (consume one character from text). 3️⃣ Continued recursively until the entire text and pattern were checked. #100DaysOfCode #LeetCode #DSA #ProblemSolving #Cplusplus #CodingChallenge #Algorithms #Programming #DeveloperLife #CodeNewbie #DailyDSA #SoftwareEngineering #CodingJourney #LearningInPublic #TechCommunity #KeepLearning #Recursion #GrowthMindset #Motivation

📅 Day 42 of #100DaysOfCode Problem: Subsets (LeetCode 78) Approach: 1️⃣ Used backtracking to explore every possibility — either include the current element or skip it. 2️⃣ When the index reaches the end, added the current subset to the result. 3️⃣ Backtracked properly to remove elements before exploring the next choice. 4️⃣ This ensures every possible combination is covered without duplicates. #100DaysOfCode #LeetCode #Backtracking #Recursion #DSA #Cplusplus #ProblemSolving #CodingChallenge #Algorithms #Programming #DeveloperLife #CodeNewbie #DailyDSA #TechCommunity #KeepLearning #GrowthMindset #SoftwareEngineering #LearningInPublic #Motivation

📅 Day 46 of #100DaysOfCode Problem: Combinations (LeetCode 77) Approach: 1️⃣ Used recursion to build combinations incrementally. 2️⃣ For every number, we have two choices — include it or skip it. 3️⃣ Once we’ve picked k numbers, added that combination to the result. 4️⃣ Used backtracking (pop_back) to explore the next possibility cleanly. #100DaysOfCode #LeetCode #DSA #Backtracking #Recursion #ProblemSolving #Cplusplus #CodingChallenge #Algorithms #Programming #DeveloperLife #CodeNewbie #SoftwareEngineering #CodingJourney #DailyDSA #KeepLearning #GrowthMindset #Motivation #TechCommunity