Heap and Priority Queue: The Data Structure Behind Top-K
Learn how heaps power priority queues, why heapq runs push and pop in O(log n), and how to solve classic Top-K and merge problems in Python.
·6 min read · #dsa#heap#beginner
#beginner
12 posts.
LeetCode Best Time to Buy and Sell Stock: One-Pass O(n)
Walk through LeetCode 121 Best Time to Buy and Sell Stock. We go from the quadratic brute force to a clean one-pass solution tracking the running minimum.
·5 min read · #dsa#leetcode#arrays
LeetCode Two Sum: Brute Force to O(n) Hash Map
A complete walkthrough of LeetCode 1 Two Sum. We move from the obvious nested loop to a single-pass hash map and dissect why it works.
·5 min read · #dsa#leetcode#hashing
Tries: The Data Structure Behind Autocomplete
A practical introduction to tries: node structure, insert, search, prefix queries, memory tradeoffs, and classic interview problems like word search.
·6 min read · #dsa#trie#beginner
C++ Control Flow: if, for, while, switch
Master C++ control flow with if-else, for and range-for loops, while, do-while, switch, and the modern init-statement syntax for conditions.
·5 min read · #cpp#control-flow#beginner
C++ Functions, References, and Pass-By-Value
Write C++ functions that pass data correctly: by value, by reference, by const reference, with overloading, default arguments, and clear ownership.
·5 min read · #cpp#functions#beginner
Install C++ and Compile Your First Program
Set up a modern C++ toolchain on macOS, Linux, or Windows, then compile and run your first program with g++ or clang++ from the command line.
·4 min read · #cpp#setup#beginner
C++ Variables and Fundamental Types
Understand C++ fundamental types, fixed-width integers, floating point, char, bool, const, and how initialization actually works in modern C++.
·5 min read · #cpp#types#beginner
Java Classes and Objects: OOP From Scratch
Design Java classes that hold state and behavior cleanly. Constructors, encapsulation, static vs instance, records, and the equals plus hashCode contract.
·5 min read · #java#oop#beginner
Java Control Flow: if, for, while, switch
Every branching and looping construct in modern Java, including switch expressions and pattern matching, with examples that mirror real code.
·5 min read · #java#control-flow#beginner
Install Java and Write Your First Program
Install a modern JDK, verify the toolchain, and ship your first Java program from the command line without an IDE doing the magic for you.
·4 min read · #java#setup#beginner
Java Variables and Primitive Types
Master Java primitives, reference types, literals, and casting. Know exactly what each type costs and where overflow and precision will bite you.
·5 min read · #java#types#beginner