What lead me to Leetcode:
I am Student and Whenever a beginner student in this dev field think about coding or programming they usually always think about making websites, apps, cool UI's, animations etc. and I was one of them, I have been making apps, websites and even games but in some space i knew i am just following the tutorials, trying and making things using existing solutions and I was not solving problems, I was not budling my problem solving skills I was just using the premade solutions. So I came across Leetcode a widely popular platform for solving problems.


What I Think Now:
When I started I didn't think much of it I thought they will be easy to solve and all so I directly jumped onto That day's Daily Problem and it was marked as Hard so first after seeing it I was scared, then I read the title I got even more scared and when I read the full Problem I was EVEN MORE SCARED seeing how brainstorming the problem that was, Even If i wasn't able to solve that problem even after seeing the solution as it so many concepts, algorithms so beautifully so solve the problem I was in love with it, so I decided that I need to become so good at solving problems that i can solve daily problems like that by myself and in the best way possible.


What I am doing Now:
After getting a Reality check I came to the problems tab and started the Easy marked problems and to my surprise even the easy problems were so good some of them really made me sweat and lead me to hours of learning the algorithms and concepts needed in those problems which i enjoyed every moment of. I am now solving Easy problems as the starting learning new things with each new problem.


What I Learned:
After solving some problems, I got to learn that coding and programming aren't just about development, but as essential the development is the main crust of coding and programming is Solving Problems. When you come across a tough problem and then we solve it the joy we get is unmatched. It Improves how we think, how we approach, how we solve.
It even indirectly improve how efficiently we code during development of even UI.


Final Thoughts:
I just wrote my heart out here, It may not be good but I am still open to Improve so I am doing it the best way i can, there are many things I haven't included like how this problems let's us manage, access data and all because I am still in early phase so I can't say much about those real topics I tried to keep it simple. But i Just want to only one thing START DOING LEETCODE, or any other platform to solve problems.

I remember in my earlier phase as a software engineer, how I mapped the MFC's command routing algorithm to Chain of Responsibility - and when finally it became clear, there was immense joy for me.I always say to my students that we should approach a problem not only from how's point of view but also from why's point of views.Curiosity is one of the greatest traits for a software engineer - nurture that, grow that - if you want to extract joy from your day-to-day journey as a software engineer.So here we go.My today's contribution to the learning community - Chain of Responsibility design pattern using Rust.The Chain of Responsibility design pattern is a behavioural design pattern that allows a request to pass through a series of handlers. Each handler can either handle the request or pass it to the next handler in the chain. This design pattern promotes loose coupling between the sender and receiver of a request, allowing more flexibility in handling specific actions.


Key Features of the Chain of Responsibility Pattern:



Decoupling:
The sender of the request doesn't need to know which handler will process the request.


Dynamic Chains:
You can change the chain of handlers at runtime or configure it based on the application's needs.


Multiple Handlers:
A request can be processed by a series of handlers in sequence until one of them handles the request, or it can propagate through all of them.Here's the source code...
⛶```
#[derive(Clone)]
struct Request{
request_type : String,
}
impl Request{
fn new(request_type : String) - Self{
Request{
request_type : request_type,
}
}
}

trait Employee {
fn set_successor(mut self, successor:Box);
fn handle_request(mut self, request: Request) ;
}
struct ProjectManager {
successor: Option,
}

struct TeamLeader {
successor: Option,
}

struct GeneralManager{
successor: Option,
}

struct CTO {
successor: Option,
}

impl Employee for CTO{

fn set_successor(mut self, successor: Box) {
//end of the chain... no successor
}
fn handle_request(mut self, request : Request) {
println!("I am the CTO... I must handle the request as this is the end of the chain");
println!("The request is handled at the CTO level...");
}
}

impl Employee for GeneralManager {
fn set_successor(mut self, successor: Box) {
self.successor = Some(successor);
}

fn handle_request(mut self, request : Request) {
if request.request_type == "generalmanager_level" {
println!("Handling the request at the General Manager level");
}
else if let Some(ref mut successor) = self.successor {
println!("I am the general manager...Forwarding the request to CTO...");
successor.handle_request(request);
}
}
}

impl Employee for ProjectManager {
fn set_successor(mut self, successor: Box) {
self.successor = Some(successor);
}

fn handle_request(mut self, request: Request) {
if request.request_type == "projectmanager_level" {
println!("Handling the request at the Project Manager level");
} else if let Some(ref mut successor) = self.successor {
println!("I am the Project Manager...Forwarding the request to General Manager");
successor.handle_request(request);
}
}
}

impl Employee for TeamLeader {
fn set_successor(mut self, successor: Box) {
self.successor = Some(successor);
}

fn handle_request(mut self, request : Request) {
if request.request_type == "teamleader_level" {
println!("Handling the request at the team_leader level");
}
else if let Some(ref mut successor) = self.successor {
println!("I am the teamleader....Forwarding the request to Project Manager");
successor.handle_request(request);
}
}
}

fn main() {
let request1 = Request::new("teamleader_level".to_string());
let request2 = Request::new("generalmanager_level".to_string());
let request3 = Request::new("cto_level".to_string());
let mut cto = CTO{successor: None};
let mut gm = GeneralManager{successor: None};
let mut manager = ProjectManager {successor: None};
let mut teamLeader = TeamLeader {successor: None};
gm.set_successor(Box::new(cto));
manager.set_successor(Box::new(gm));
teamLeader.set_successor(Box::new(manager));
teamLeader.handle_request(request3);
}
```Enjoy...

Retrieval-Augmented Generation (RAG) has become one of the most popular techniques in AI because it helps models stay up to date and reduce hallucinations. But as the need for more advanced use cases grew, RAG itself evolved into different types. Each version solves a different challenge, from answering simple queries to tackling complex reasoning tasks.?Breaking It DownAt its core, RAG works by pulling information from an external source before generating an answer. For a simple fact-based question like “What is the capital of Japan?”, a vanilla RAG system searches, finds “Tokyo,” and responds. But what if the query requires multiple steps, reasoning, or access to tools? That’s where other versions of RAG come in.? Different Types of RAG1. Vanilla RAG
The simplest version. It retrieves once and then generates.
Example: Asking “Who is the CEO of Apple?”2. Agentic RAG
Here, AI acts like an agent. It doesn’t just retrieve but can also plan steps, call APIs, or use calculators before answering.
Example: “Compare Apple’s last 5 earnings and summarize growth.”3. Multi-hop RAG
This approach breaks complex queries into smaller parts, retrieves multiple times, and combines results.
Example: “Who was the mentor of the scientist who developed the polio vaccine?”4. Hybrid RAG
Combines keyword search with semantic (vector) search to increase accuracy.
Example: Searching through medical literature where meaning and exact terms both matter.? Do’s and Don’tsDo:
✔ Use vanilla RAG for simple, fact-based answers.
✔ Use agentic RAG when reasoning or tool usage is needed.
✔ Use multi-hop for layered or indirect queries.
✔ Use hybrid when working with specialized domains like law or medicine.Don’t:
❌ Don’t apply vanilla RAG for highly complex tasks → it will likely fail.
❌ Don’t ignore retrieval quality → poor document selection leads to bad answers.
❌ Don’t overload multi-hop RAG with unnecessary hops that increase cost and latency.? Real-World Applications

Vanilla RAG: Chatbots answering FAQs.

Agentic RAG: AI assistants that fetch and analyze financial data.

Multi-hop RAG: Research tools connecting historical references.

Hybrid RAG: Legal and healthcare assistants working with precise documents.
? Closing ThoughtRAG isn’t a single technique anymore → it’s a toolkit with multiple flavors. Vanilla handles the basics, agentic brings reasoning, multi-hop tackles complexity, and hybrid ensures precision. The right choice depends on your use case, data type, and performance needs.