java_progress/ └── src/ ├── Basics/ # Java fundamentals — data types, I/O, operators, type casting ├── Conditionals/ # If-else, switch, nested conditions ├── Loops/ # Loop patterns and practice ├── Methods/ # Functions, overloading, varargs, recursion ├── Arrays/ # Array & ArrayList operations, 2D arrays, passing in functions ├── Strings/ # String methods, builders, palindrome, comparisons ├── Numbers/ # Armstrong, Fibonacci, prime, number reversal ├── Searching/ # Linear search, Binary search (ascending/descending/2D/order-agnostic) ├── Sorting/ # Bubble, Selection, Insertion, Cycle, Merge sort + recursive variants ├── Recursion/ # Recursion fundamentals — sorting, searching, patterns, maths ├── Questions/ # Practice questions — Arrays, BitOps, Numbers, Patterns, Recursion ├── Notes/ # Reference notes └── LeetCode/ ├── Arrays/ # 48 files — Two Sum, Missing Number, Greedy, Asteroids… ├── BinarySearch/ # 13 files — Rotated arrays, peak finding, mountain array… ├── Strings/ # 27 files — Anagram, palindrome, sliding window, password… ├── TwoPointers/ # 7 files — Valid Palindrome, Move Zeroes, Happy Number… ├── BitManipulation/ # 3 files — Reverse Bits, Number of 1 Bits, Steps to Zero ├── Math/ # 8 files — Power of Two, Ugly Number, Fizz Buzz… ├── Recursion/ # 1 file — Steps to Reduce Number to Zero └── Misc/ # 4 files — Isomorphic Strings, Richest Customer Wealth…