Minimum Distance Between Start Index and Target in Array

🔥 Day 36 of #LeetCode Journey ✅ Problem: Minimum Distance Between Three Equal Elements I Today’s problem was about finding the minimum distance between three equal elements in an array. 💡 Key Idea: Instead of checking all combinations, we track indices efficiently: Store the last two occurrences of each number When a third occurrence appears, calculate the distance Keep updating the minimum distance 🧠 What I Learned: Optimizing from brute force to O(n) approach Using HashMap effectively for tracking indices Thinking in terms of patterns instead of combinations ⚡ Time Complexity: O(n) ⚡ Space Complexity: O(n) 🔍 Example: Input: [1,2,1,1,3,1] Output: 3 Small optimizations make a big difference 💡 Staying consistent and improving every day! #Java #DSA #LeetCode #CodingJourney #100DaysOfCode #Programming #ProblemSolving

What happened when run the code ? @RestController public class TestController { @Autowired private TestService testService; public TestController() { System.out.println(testService.getMessage()); } } Looks correct but throw error ? Answer: NullPointerException Why : spring inject dependencies after constructer execution so testService is null inside constructer #Spring flow is: 1. Object is created (constructor runs first) 2. Then dependency injection happens (@Autowired) #SpringBoot #Java #Backend #CodingInterview #FAANG #Microservices #Programming #Developers

I recently encountered an ambiguous mapping error while working on a REST API. The stack trace was overwhelming, but the message was straightforward : I had two different methods competing for the same URL and HTTP verb. The issue happened because I had two methods, createEmployee and createNewEmployee, both annotated with @PostMapping, along with @RequestMapping on the controller class. Spring couldn't determine which method to use to handle the request. To resolve this, it's essential to keep the endpoints unique or utilize different HTTP methods to maintain organization. Happy coding! #Java #SpringBoot #Programming #SoftwareEngineering #Debugging

🚀 Day 15 of 180 — 3Sum Closest ✅ LeetCode 16 — 3Sum Closest First sort the array. Then fix one element and use two pointers for the remaining two — one at left, one at right. For every triplet I calculate the sum and check how far it is from the target: distance = |target - sum| If this distance is less than my current minimum difference, I update my answer. Moving pointers is simple — if sum is greater than target → move right pointer left if sum is less than target → move left pointer right if sum equals target → that's the closest it can get, return immediately The key thing I made sure — keep tracking the minimum difference throughout and update result whenever a closer sum is found. Day 15 done. 165 to go. 🔥 #180DaysDSA #Day15 #LeetCode #Java #DSA #TwoPointers #Sorting #ThreeSum #DSAJourney #CodingJourney #Programming #DataStructures #Algorithms #ProblemSolving #BuildInPublic #CodeNewbie #LearnToCode #100DaysOfCode #SoftwareDevelopment #Developer #StudentDeveloper #TechCommunity #LinkedInTech #CompetitiveProgramming

Debugged & Optimized: Beats 100% on LeetCode! 🚀 By switching to a Two-Pass O(n) logic in Java, I was able to find all valid elements while beating 100% of submissions in speed. Key Takeaway: Debugging is just as important as coding. Sticking with the problem until the logic is optimal is where the real learning happens. Onwards to more complex challenges! #Java #DSA #LeetCode #ProblemSolving #Engineering

🚀 Code 3 – #50LeetCodeChallenge Problem: 4Sum Given an array of integers and a target value, find all unique quadruplets that sum up to the target. Each element must be used only once, and the solution set should not contain duplicate combinations. 💡 Approach: Sort the array and use nested loops along with a two-pointer technique to find combinations efficiently. Skip duplicate elements to ensure only unique quadruplets are included. 📚 Key Takeaway: Combining sorting with the two-pointer approach helps reduce complexity and is highly effective for solving multi-sum problems like 4Sum. #LeetCode #Java #Coding #ProblemSolving #Arrays #TwoPointers #Programming

Many beginners use Spring annotations like @Autowired and @Component daily, but don’t fully understand what happens behind the scenes. The real magic happens inside the Spring IoC Container. Here’s the step-by-step flow: Spring reads configuration Bean definitions are created IoC container initializes Beans are instantiated Dependencies are injected Lifecycle methods are called Beans become ready to use Destroy methods run when the application stops Without IoC: You manually create objects and manage dependencies. With Spring IoC: Spring creates, manages, and injects everything for you. Example: Engine engine = new Engine(); Car car = new Car(engine); vs Car car = context.getBean(Car.class); That’s why Spring applications stay cleaner, more scalable, and easier to maintain. Key concepts: BeanFactory ApplicationContext Dependency Injection Bean Lifecycle Autowiring Bean Scope If you are learning Spring Boot, understanding IoC is one of the most important fundamentals. #SpringBoot #Java #BackendDevelopment #SoftwareEngineering #Programming #Developers #Coding #JavaDeveloper #DependencyInjection #SpringFramework

🚀 Code 5– #50LeetCodeChallenge 🧩 Problem: Remove Element Given an array and a value val, remove all occurrences of val in-place and return the count of remaining elements. The order of elements can be changed. 💡 Approach: Use a two-pointer technique—one pointer iterates through the array, while the other keeps track of the position to place elements that are not equal to val. 📚 Key Takeaway: In-place modification with two pointers helps achieve O(n) time complexity and O(1) space, making it efficient for array filtering problems. #LeetCode #Java #Coding #ProblemSolving #Arrays #TwoPointers #Programming

💫@𝐏𝐫𝐢𝐦𝐚𝐫𝐲 𝐯𝐬 @𝐐𝐮𝐚𝐥𝐢𝐟𝐢𝐞𝐫 𝐢𝐧 𝐒𝐩𝐫𝐢𝐧𝐠 𝐁𝐨𝐨𝐭: When working with dependency injection in Spring Boot, handling multiple beans of the same type can get tricky. That’s where @Primary and @Qualifier come into play 👇 👉 @Primary Used to define a default bean. If multiple beans exist, Spring automatically picks the one marked as @Primary. 👉 @Qualifier Used to explicitly specify which bean you want. Gives you precise control over dependency injection. 💡 Key Insight: Use @Primary for default behavior and @Qualifier when you need specific control. Together, they make your code more flexible and maintainable. #SpringBoot #JavaDeveloper #BackendDevelopment #DependencyInjection #SpringFramework #Java #Coding #SoftwareDevelopment #TechLearning #Developers #Programming #100DaysOfCode #JavaBackend #SpringAnnotations 𝐓𝐡𝐚𝐧𝐤𝐬 𝐭𝐨 𝐦𝐲 𝐌𝐞𝐧𝐭𝐨𝐫: Anand Kumar Buddarapu Saketh Kallepu Uppugundla Sairam