Find Mode in Binary Search Tree using Inorder Traversal

🚀 Day 22 of Consistency | #75DaysLeetCodeChallenge 🧠 Today’s Problem : Daily Temperatures (#739) 💡 Key Learning: This problem introduces the concept of a monotonic stack, useful for solving “next greater element” type problems efficiently. ⚡ Approach: Use a stack to store indices of temperatures Traverse the array → While current temp > stack top temp → pop & calculate days difference Store result for popped indices Push current index to stack 🧠 Why this works: Monotonic stack keeps decreasing order Helps find next greater element in O(n) Avoids brute force O(n²) 🔥 Result : ✔️ Runtime: 116 ms (Beats 28.07%) 📈 A very important pattern for stack-based optimization problems. A big thanks to Shivam Singh, Nikhil Yadav & Akshat Tiwari for this amazing challenge 🙌 Consistency is compounding. Keep going. 💪 #Day22 #LeetCode #DSA #CodingJourney #100DaysOfCode #Python #Stack #Consistency

🚀 Day 39/60 — LeetCode Discipline Problem Solved: Sqrt(x) Difficulty: Easy Today’s challenge was to compute the square root of a number without using built-in functions. Instead of brute force, I used Binary Search — a classic, elegant approach that narrows down the answer efficiently. 💡 Key Learnings: • Binary Search application beyond arrays • Handling edge cases (x < 2) • Avoiding overflow using conditions carefully • Finding floor value of square root • Optimized thinking over brute force ⚡ Performance: Runtime: 4 ms Like walking in a foggy path, I didn’t see the answer directly… But step by step— cutting the search space in half— the truth revealed itself. That’s the beauty of algorithms. #LeetCode #60DaysOfCode #DSA #BinarySearch #ProblemSolving #CodingJourney #Python #Consistency #TechGrowth

From Linear Regression to Logistic Regression. After building Linear Regression from scratch, I wanted to take the next step — solving a classification problem. I implemented Logistic Regression the same way (no libraries), to classify whether an email is Spam or Not Spam. - What I did: Implemented the sigmoid function to convert outputs into probabilities Built the prediction logic for binary classification Used gradient descent to optimize parameters (w, b) Applied a threshold (0.5) to classify outputs - What I learned: Difference between regression (continuous output) and classification (probability-based output) How sigmoid creates an S-shaped curve for decision making Why loss functions like log loss are used in classification - Result: The model learns to classify based on input activity and outputs probabilities. Example: Activity: 3.0 → Probability: ~0.90 → Spam 🔗 Code: https://lnkd.in/g_MygMKc #MachineLearning #Python #LogisticRegression #LearningInPublic

Day 14/100 – Data Structures & Algorithms Today, I worked on the problem “First Unique Character in a String.” Overview The task is to identify the first non-repeating character in a string and return its index. If no such character exists, the result is -1. Approach I used a two-pass strategy: • First pass to store character frequencies using a hashmap • Second pass to identify the first character with a frequency of one Complexity • Time Complexity: O(n) • Space Complexity: O(1) Key Takeaway This problem reinforces how effective hashmaps are for frequency-based problems and how a simple two-pass approach can lead to optimal solutions. Staying consistent and building problem-solving intuition step by step. #Day14 #100DaysOfCode #DSA #Python #LeetCode #ProblemSolving #SoftwareEngineering

Day 118 Backtracking patterns are repeating — and getting clearer. #Day118 🧩 39. Combination Sum How today went: • Used index i to control choices • Two options at each step: → stay at i (reuse same element) → move to i + 1 (try next element) • Track current total • If total == target → store result • If total > target → backtrack What clicked: It’s all about: → controlling index → tracking total → backtracking at the right time Same pattern, more confidence. #LeetCode #DSA #Python #Backtracking #Recursion #LearningInPublic #Consistency

Day 20 of My DSA Journey – Daily Temperatures Today’s problem: Daily Temperatures 🌡️ A great example of how switching from brute force to the right data structure changes everything. 🔍 Problem Given a list of temperatures, find how many days you need to wait for a warmer day. If no warmer day exists, return 0. 💡 What I Learned At first glance, a nested loop feels natural… but that leads to O(n²) time complexity ❌ The optimized solution uses a Monotonic Stack to reduce it to O(n) ✅ ⚡ Approach Use a stack to store indices of unresolved temperatures Traverse the array once When a warmer temperature appears → resolve previous days Store the difference in indices #Day20 #DSA #LeetCode #Python #CodingJourney #ProblemSolving #100DaysOfCode

Built a Rainfall Prediction model and deployed it live. Here is what actually happened behind the scenes Decision Tree gave me 100% training accuracy. I got excited. Then I checked the test score and realised the model had just memorised the data. It learned nothing real. Naive Bayes gave me 73.9% on both train and test. Consistent That is the one I deployed. 3 models trained. 1 deployed. 1 lesson — a consistent score beats a perfect score every time live app here: https://lnkd.in/d-xaufug Full project and code: https://lnkd.in/d_d2Tx7R Akarsh Vyas Tanishq Vyas #DataScience #MachineLearning #Python #Streamlit #BuildInPublic #MLProject

🚀 Day 28 of Problem Solving Journey Today, I worked on an interesting problem: Group Anagrams 🔍 Problem Statement: Given an array of strings, group the anagrams together. Anagrams are words that have the same characters but arranged differently. 💡 Approaches I explored: ✅ Approach 1: Character Frequency Count (Optimized) Used a fixed-size array (26 letters) to count character occurrences Converted the count into a tuple to use as a dictionary key Achieved an efficient time complexity of O(n * k) ✅ Approach 2: Sorting Strings Sorted each string and used it as a key Simple and intuitive approach Time complexity: O(n * k log k) 📌 Key Learning: Understanding how hashing works with different representations (frequency vs sorted string) helps in optimizing solutions. ⚡ Takeaway: There are always multiple ways to solve a problem, but choosing the most efficient one makes a difference in real-world applications and interviews. 💻 Tech Used: Python | HashMap | Arrays #Day28 #ProblemSolving #Python #DataStructures #Algorithms #CodingJourney #100DaysOfCode

Days 68-69 of the #three90challenge 📊 Today I explored NumPy operations — specifically indexing and slicing arrays. After understanding NumPy basics, this step made it easier to access and manipulate data efficiently. What I practiced today: • Accessing elements using indexing • Extracting subsets of data using slicing • Working with multi-dimensional arrays • Performing operations on selected data Example thinking: Instead of looping through data manually, I can directly select and operate on specific parts of an array. Example: import numpy as np arr = np.array([10, 20, 30, 40, 50]) print(arr[1:4]) # Output: [20 30 40] This makes data manipulation faster and more intuitive. From handling data → to controlling it efficiently 🚀 GeeksforGeeks #three90challenge #commitwithgfg #Python #NumPy #DataAnalytics #LearningInPublic #Consistency #Upskilling

LeetCode Problem 1448. Count Good Nodes in Binary Tree: "Given a binary tree root, a node X in the tree is named good if in the path from root to X there are no nodes with a value greater than X. Return the number of good nodes in the binary tree." Approach: make use of pre-order traversal i.e., visit root->left->right child, in each visit, keep track of the max element upto that point by maintaining a stack, top of the stk should represent the max element upto that point in the path, pop() elements from stack when both the children (left,right) are explored. Time Complexity: O(n) Space Complexity: O(n) b/c of maintaining a stack #Python #LeetCode #DSA #DataStructures #Algorithms #Stack #Recursion #DFS #BinaryTree #ProblemSolving