diff --git a/Arrays/Anagram_Check_manual_Sol.py b/Arrays/AnagramCheckManualSol.py similarity index 100% rename from Arrays/Anagram_Check_manual_Sol.py rename to Arrays/AnagramCheckManualSol.py diff --git a/Arrays/Anagram_Check_Sorted_Sol.py b/Arrays/AnagramCheckSortedSol.py similarity index 100% rename from Arrays/Anagram_Check_Sorted_Sol.py rename to Arrays/AnagramCheckSortedSol.py diff --git a/Arrays/ArrayFindTheMissingElement_brute_force_sol.py b/Arrays/ArrayFindTheMissingElementBruteForceSol.py similarity index 100% rename from Arrays/ArrayFindTheMissingElement_brute_force_sol.py rename to Arrays/ArrayFindTheMissingElementBruteForceSol.py diff --git a/Arrays/ArrayFindTheMissingElement_hash_table_sol.py b/Arrays/ArrayFindTheMissingElementHashTableSol.py similarity index 100% rename from Arrays/ArrayFindTheMissingElement_hash_table_sol.py rename to Arrays/ArrayFindTheMissingElementHashTableSol.py diff --git a/Arrays/ArrayFindTheMissingElement_takingSumandSubtract_sol.py b/Arrays/ArrayFindTheMissingElementSumSol.py similarity index 100% rename from Arrays/ArrayFindTheMissingElement_takingSumandSubtract_sol.py rename to Arrays/ArrayFindTheMissingElementSumSol.py diff --git a/Arrays/ArrayFindTheMissingElement_XOR_sol.py b/Arrays/ArrayFindTheMissingElementXORSol.py similarity index 100% rename from Arrays/ArrayFindTheMissingElement_XOR_sol.py rename to Arrays/ArrayFindTheMissingElementXORSol.py diff --git a/Arrays/README.md b/Arrays/README.md index 707a82e..a9d129c 100644 --- a/Arrays/README.md +++ b/Arrays/README.md @@ -4,10 +4,10 @@ This directory contains Python implementations of common array-based algorithms ## Contents -- [Anagram Check (Sorted Solution)](Anagram_Check_Sorted_Sol.py): Checks if two strings are anagrams by comparing their sorted versions. -- [Anagram Check (Manual Solution)](Anagram_Check_manual_Sol.py): Checks if two strings are anagrams using a hash table (dictionary) to count character frequencies. -- [Array Find Missing Element (XOR Solution)](ArrayFindTheMissingElement_XOR_sol.py): Efficiently finds a missing element in a shuffled array using bitwise XOR. -- [Array Find Missing Element (Brute Force Solution)](ArrayFindTheMissingElement_brute_force_sol.py): Finds a missing element by sorting both arrays and comparing them. -- [Array Find Missing Element (Hash Table Solution)](ArrayFindTheMissingElement_hash_table_sol.py): Finds a missing element using a hash table (dictionary) to track element counts. -- [Array Find Missing Element (Sum/Subtract Solution)](ArrayFindTheMissingElement_takingSumandSubtract_sol.py): Finds a missing element by calculating the difference between the sums of the two arrays. -- [Array Pair Sum Solution](ArrayPairSumSol.py): Finds all unique pairs in an array that sum up to a specific value $k$ using a set for $O(n)$ complexity. +- [Anagram Check (Sorted Solution)](AnagramCheckSortedSol.py): Checks if two strings are anagrams by comparing their sorted versions. Complexity: $O(n \log n)$. +- [Anagram Check (Manual Solution)](AnagramCheckManualSol.py): Checks if two strings are anagrams using a hash table (dictionary) to count character frequencies. Complexity: $O(n)$. +- [Array Find Missing Element (XOR Solution)](ArrayFindTheMissingElementXORSol.py): Efficiently finds a missing element in a shuffled array using bitwise XOR. Complexity: $O(n)$ time, $O(1)$ space. +- [Array Find Missing Element (Brute Force Solution)](ArrayFindTheMissingElementBruteForceSol.py): Finds a missing element by sorting both arrays and comparing them. Complexity: $O(n \log n)$. +- [Array Find Missing Element (Hash Table Solution)](ArrayFindTheMissingElementHashTableSol.py): Finds a missing element using a hash table (dictionary) to track element counts. Complexity: $O(n)$. +- [Array Find Missing Element (Sum/Subtract Solution)](ArrayFindTheMissingElementSumSol.py): Finds a missing element by calculating the difference between the sums of the two arrays. Complexity: $O(n)$. +- [Array Pair Sum Solution](ArrayPairSumSol.py): Finds all unique pairs in an array that sum up to a specific value $k$ using a set. Complexity: $O(n)$. diff --git a/deque/DequeImple.py b/Deque/DequeImple.py similarity index 100% rename from deque/DequeImple.py rename to Deque/DequeImple.py diff --git a/deque/README.md b/Deque/README.md similarity index 57% rename from deque/README.md rename to Deque/README.md index 046a17f..8a1aab8 100644 --- a/deque/README.md +++ b/Deque/README.md @@ -4,4 +4,4 @@ This directory contains Python implementations of the Deque (Double-Ended Queue) ## Contents -- [Deque Implementation](DequeImple.py): Basic implementation of a Deque using a Python list. Includes operations like `addFront`, `addRear`, `removeFront`, `removeRear`, `isEmpty`, and `size`. +- [Deque Implementation](DequeImple.py): Basic implementation of a Deque using a Python list. Complexity: $O(1)$ for `addFront`/`removeFront`, $O(n)$ for `addRear`/`removeRear` due to list shifting. diff --git a/Error-debug/ErrorExceptions.py b/ErrorHandling/ErrorExceptions.py similarity index 100% rename from Error-debug/ErrorExceptions.py rename to ErrorHandling/ErrorExceptions.py diff --git a/Error-debug/README.md b/ErrorHandling/README.md similarity index 100% rename from Error-debug/README.md rename to ErrorHandling/README.md diff --git a/GraphAlgorithms/README.md b/GraphAlgorithms/README.md index f0330f8..43b9d59 100644 --- a/GraphAlgorithms/README.md +++ b/GraphAlgorithms/README.md @@ -4,9 +4,9 @@ This directory contains Python implementations of common graph-based algorithms ## Contents -- [Adjacency List Implementation](AdjacencyListGraphImple.py): Implements the Graph Abstract Data Type (ADT) using an adjacency list (dictionaries in Python). Includes `Vertex` and `Graph` classes. -- [Breadth First Search (BFS)](BFS.py): Implements BFS to solve the Word Ladder problem, finding the shortest transformation path between words. -- [General Depth First Search (DFS)](DFSGeneral.py): Provides a general implementation of DFS, including discovery and finish times for vertices. -- [DFS - Knight's Tour Problem](DFSImpleTheKnightsTourProblem.py): Another implementation of DFS specifically tailored to the Knight's Tour puzzle. -- [The Knight's Tour Problem](TheKnightsTourProblem.py): Focuses on generating the knight's move graph and solving the tour using DFS and backtracking. -- [Word Ladder Problem](WordLadderProblem.py): Specifically focuses on building the word ladder graph where edges connect words that differ by only one letter. +- [Adjacency List Implementation](AdjacencyListGraphImple.py): Implements the Graph ADT using an adjacency list. Complexity: $O(1)$ to add vertex/edge. +- [Breadth First Search (BFS)](BFS.py): Implements BFS to solve the Word Ladder problem. Complexity: $O(V + E)$. +- [General Depth First Search (DFS)](DFSGeneral.py): Provides a general implementation of DFS. Complexity: $O(V + E)$. +- [DFS - Knight's Tour Problem](DFSImpleTheKnightsTourProblem.py): Specifically tailored DFS for the Knight's Tour. Complexity: $O(k^N)$ exponential. +- [The Knight's Tour Problem](TheKnightsTourProblem.py): Generates the knight's move graph. +- [Word Ladder Problem](WordLadderProblem.py): Specifically focuses on building the word ladder graph. diff --git a/LinkedLists/README.md b/LinkedLists/README.md index bead21d..da58581 100644 --- a/LinkedLists/README.md +++ b/LinkedLists/README.md @@ -4,8 +4,8 @@ This directory contains Python implementations of various types of linked lists ## Contents -- [Singly Linked List Implementation](SingleLinkedListImple.py): Basic implementation of a singly linked list node and basic linkage. -- [Doubly Linked List Implementation](DoublyLinkedListImple.py): Basic implementation of a doubly linked list node with `prev` and `next` pointers. -- [Singly Linked List Cycle Check](SinglyLinkedListCycleCheckImple.py): Implements Floyd's Cycle-Finding Algorithm (two pointers) to detect cycles in a linked list. -- [Linked List Reversal](LinkedListReversal.py): Reverses a singly linked list in-place in $O(n)$ time. -- [Nth to Last Node](LinkedListNthToLastNode.py): Finds the $n$-th to last node in a singly linked list using two pointers. +- [Singly Linked List Implementation](SingleLinkedListImple.py): Basic implementation of a singly linked list node and basic linkage. Complexity: $O(1)$ for insertion/deletion at head. +- [Doubly Linked List Implementation](DoublyLinkedListImple.py): Basic implementation of a doubly linked list node with `prev` and `next` pointers. Complexity: $O(1)$ for insertion/deletion at head/tail. +- [Singly Linked List Cycle Check](SinglyLinkedListCycleCheckImple.py): Implements Floyd's Cycle-Finding Algorithm (two pointers) to detect cycles. Complexity: $O(n)$ time, $O(1)$ space. +- [Linked List Reversal](LinkedListReversal.py): Reverses a singly linked list in-place. Complexity: $O(n)$. +- [Nth to Last Node](LinkedListNthToLastNode.py): Finds the $n$-th to last node in a singly linked list using two pointers. Complexity: $O(n)$. diff --git a/Queues/README.md b/Queues/README.md index a1c90d0..803693b 100644 --- a/Queues/README.md +++ b/Queues/README.md @@ -4,5 +4,5 @@ This directory contains Python implementations of the Queue data structure. ## Contents -- [Queue Implementation](QueueImple.py): Basic implementation of a FIFO (First-In-First-Out) queue using a Python list. Includes `enqueue`, `dequeue`, `isEmpty`, and `size` methods. -- [Queue with Two Stacks](QueueWith2StacksImple.py): Implements a queue using two stacks (represented by Python lists) to achieve FIFO behavior. +- [Queue Implementation](QueueImple.py): Basic implementation of a FIFO (First-In-First-Out) queue using a Python list. Complexity: $O(n)$ for enqueue (using `insert(0)`), $O(1)$ for dequeue (using `pop()`). +- [Queue with Two Stacks](QueueWith2StacksImple.py): Implements a queue using two stacks. Complexity: $O(1)$ amortized for both enqueue and dequeue. diff --git a/README.md b/README.md index b8de7d5..e394f68 100644 --- a/README.md +++ b/README.md @@ -35,22 +35,22 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for more details. ## πŸ“– Table of Contents -- [Getting Started](#getting-started) -- [Project Structure](#project-structure) -- [Data Structures](#data-structures) - - [Arrays](#arrays) - - [Linked Lists](#linked-lists) - - [Stacks](#stacks) - - [Queues](#queues) - - [Deque](#deque) - - [Trees](#trees) -- [Algorithms](#algorithms) - - [Sorting](#sorting) - - [Recursion & Dynamic Programming](#recursion--dynamic-programming) - - [Graph Algorithms](#graph-algorithms) -- [Error Handling & Debugging](#error-handling--debugging) +- [Getting Started](#-getting-started) +- [Project Structure](#-project-structure) +- [Data Structures](#-data-structures) + - [Arrays](#arrays-) + - [Linked Lists](#linked-lists-) + - [Stacks](#stacks-) + - [Queues](#queues-) + - [Deque](#deque-) + - [Trees](#trees-) +- [Algorithms](#-algorithms) + - [Sorting](#sorting-) + - [Recursion & Dynamic Programming](#recursion--dynamic-programming-) + - [Graph Algorithms](#graph-algorithms-) +- [Error Handling & Debugging](#-error-handling--debugging) - [Usage](#usage) -- [Quick Reference](#quick-reference) +- [Quick Reference](#-quick-reference) - [License](#license) --- @@ -67,7 +67,7 @@ Most scripts in this repository are standalone and can be executed directly: ```bash # Run any Python script -python3 Arrays/Anagram_Check_Sorted_Sol.py +python3 Arrays/AnagramCheckSortedSol.py # Or run from the repo root python3 Sorting/BubbleSortImple.py @@ -80,7 +80,8 @@ python3 Sorting/BubbleSortImple.py ``` . β”œβ”€β”€ Arrays/ # πŸ”€ Array-based problems and algorithms -β”œβ”€β”€ Error-debug/ # ⚠️ Error handling and debugging examples +β”œβ”€β”€ Deque/ # πŸ”„ Double-ended queue +β”œβ”€β”€ ErrorHandling/ # ⚠️ Error handling and debugging examples β”œβ”€β”€ GraphAlgorithms/ # πŸ—ΊοΈ Graph traversal (BFS, DFS) and pathfinding β”œβ”€β”€ LinkedLists/ # πŸ”— Singly and Doubly Linked Lists β”œβ”€β”€ Queues/ # πŸ“¦ Queue implementations (FIFO) @@ -88,7 +89,6 @@ python3 Sorting/BubbleSortImple.py β”œβ”€β”€ Sorting/ # πŸ“Š Common sorting algorithms β”œβ”€β”€ Stacks/ # πŸ“š Stack implementations and applications β”œβ”€β”€ Trees/ # 🌳 Binary Trees, BSTs, Heaps, and Traversals -β”œβ”€β”€ deque/ # πŸ”„ Double-ended queue β”œβ”€β”€ CONTRIBUTING.md # 🀝 Contribution guidelines β”œβ”€β”€ LICENSE # πŸ“„ MIT License └── README.md # πŸ“– This file @@ -100,9 +100,9 @@ python3 Sorting/BubbleSortImple.py ### Arrays πŸ”€ Common array-based algorithms and manipulations. -- [Anagram Check](Arrays/): [Sorted](Arrays/Anagram_Check_Sorted_Sol.py) & [Manual](Arrays/Anagram_Check_manual_Sol.py) solutions +- [Anagram Check](Arrays/): [Sorted](Arrays/AnagramCheckSortedSol.py) & [Manual](Arrays/AnagramCheckManualSol.py) solutions - [Array Pair Sum](Arrays/ArrayPairSumSol.py): Find pairs that sum to $k$ -- [Find Missing Element](Arrays/): [XOR](Arrays/ArrayFindTheMissingElement_XOR_sol.py), [Brute Force](Arrays/ArrayFindTheMissingElement_brute_force_sol.py), [Hash Table](Arrays/ArrayFindTheMissingElement_hash_table_sol.py), & [Sum](Arrays/ArrayFindTheMissingElement_takingSumandSubtract_sol.py) approaches +- [Find Missing Element](Arrays/): [XOR](Arrays/ArrayFindTheMissingElementXORSol.py), [Brute Force](Arrays/ArrayFindTheMissingElementBruteForceSol.py), [Hash Table](Arrays/ArrayFindTheMissingElementHashTableSol.py), & [Sum](Arrays/ArrayFindTheMissingElementSumSol.py) approaches ### Linked Lists πŸ”— Implementations and problems involving linked structures. @@ -123,7 +123,7 @@ FIFO (First-In-First-Out) data structures. ### Deque πŸ”„ Double-ended queue operations. -- [Deque Implementation](deque/DequeImple.py): Operations at both ends +- [Deque Implementation](Deque/DequeImple.py): Operations at both ends ### Trees 🌳 Hierarchical data structures. @@ -133,7 +133,7 @@ Hierarchical data structures. - [Binary Heap](Trees/BinaryHeapImple.py): Min-heap implementation - [Tree Traversals](Trees/TreeLevelOrderPrintImple.py): Level order (BFS) printing - [Trim BST](Trees/TrimBinarySearchTreeImple.py): Keep nodes within a range -- [Tree Representations](Trees/): [Nodes & References](Trees/TreeRepresentationWithNodesReferences.py) & [List of Lists](Trees/buildTreeTest.py) +- [Tree Representations](Trees/): [Nodes & References](Trees/TreeRepresentationWithNodesReferences.py) & [List of Lists](Trees/BuildTreeTest.py) --- @@ -168,7 +168,7 @@ Algorithms for graph traversal and pathfinding. ## ⚠️ Error Handling & Debugging -- [Error and Exceptions](Error-debug/ErrorExceptions.py): Demonstrates `try`, `except`, `else`, and `finally` blocks for robust error handling. +- [Error and Exceptions](ErrorHandling/ErrorExceptions.py): Demonstrates `try`, `except`, `else`, and `finally` blocks for robust error handling. --- diff --git a/Recursion/README.md b/Recursion/README.md index 7265340..8ace4d0 100644 --- a/Recursion/README.md +++ b/Recursion/README.md @@ -5,17 +5,17 @@ This directory contains Python implementations of problems solved using recursio ## Contents ### Fibonacci Sequence -- [Fibonacci (Iterative)](FibonacciSeqIterative.py): Iterative implementation of the Fibonacci sequence. -- [Fibonacci (Recursive)](FibonacciSeqRecursion.py): Simple recursive implementation of the Fibonacci sequence. -- [Fibonacci (Dynamic Programming)](FibonacciSeqDynamic.py): Optimized Fibonacci sequence using memoization. +- [Fibonacci (Iterative)](FibonacciSeqIterative.py): Iterative implementation. Complexity: $O(n)$. +- [Fibonacci (Recursive)](FibonacciSeqRecursion.py): Simple recursive implementation. Complexity: $O(2^n)$. +- [Fibonacci (Dynamic Programming)](FibonacciSeqDynamic.py): Optimized using memoization. Complexity: $O(n)$. ### Coin Change Problem -- [Coin Change (Recursive)](CoinChangeProblemRecursion.py): Basic recursive solution to find the minimum number of coins for change. -- [Coin Change (Dynamic Programming)](CoinChangeProblemDynamic.py): Optimized solution to the coin change problem using dynamic programming. +- [Coin Change (Recursive)](CoinChangeProblemRecursion.py): Basic recursive solution. Complexity: Exponential. +- [Coin Change (Dynamic Programming)](CoinChangeProblemDynamic.py): Optimized using DP. Complexity: $O(n \cdot m)$ where $m$ is the number of coins. ### Other Recursive Problems -- [Cumulative Sum](RecursionCumulativeSum.py): Computes the cumulative sum from 0 to $n$ recursively. -- [Reverse a String](RecursionReverseStr.py): Reverses a string using recursive calls. -- [String Permutations](RecursionStrPermutation.py): Generates all possible permutations of a given string. -- [Sum of Digits](RecursionSumOfDigits.py): Calculates the sum of all individual digits in an integer recursively. -- [Word Split](RecursionWordSplit.py): Determines if a string can be split into words from a given list. +- [Cumulative Sum](RecursionCumulativeSum.py): Computes the cumulative sum from 0 to $n$ recursively. Complexity: $O(n)$. +- [Reverse a String](RecursionReverseStr.py): Reverses a string using recursive calls. Complexity: $O(n)$. +- [String Permutations](RecursionStrPermutation.py): Generates all possible permutations. Complexity: $O(n!)$. +- [Sum of Digits](RecursionSumOfDigits.py): Calculates the sum of digits recursively. Complexity: $O(\log_{10} n)$. +- [Word Split](RecursionWordSplit.py): Dynamic Programming solution. Complexity: $O(n^2)$ depending on dictionary lookups. diff --git a/Sorting/README.md b/Sorting/README.md index 0b76399..8a055eb 100644 --- a/Sorting/README.md +++ b/Sorting/README.md @@ -4,9 +4,9 @@ This directory contains Python implementations of various sorting algorithms wit ## Contents -- [Bubble Sort](BubbleSortImple.py): Implementation of Bubble Sort with $O(n^2)$ complexity. -- [Selection Sort](SelectionSortImple.py): Implementation of Selection Sort, improving on Bubble Sort by making only one exchange per pass. -- [Insertion Sort](InsertionSortImple.py): Implementation of Insertion Sort, maintaining a sorted sublist. -- [Shell Sort](ShellSortImple.py): Implementation of Shell Sort (diminishing increment sort), improving on Insertion Sort. -- [Merge Sort](MergeSortImple.py): A recursive "divide and conquer" algorithm with $O(n \log n)$ complexity. -- [Quick Sort](QuickSortImple.py): Implementation of Quick Sort (partition exchange sort), using divide and conquer in-place. +- [Bubble Sort](BubbleSortImple.py): Implementation of Bubble Sort. Complexity: $O(n^2)$. +- [Selection Sort](SelectionSortImple.py): Implementation of Selection Sort. Complexity: $O(n^2)$. +- [Insertion Sort](InsertionSortImple.py): Implementation of Insertion Sort. Complexity: $O(n^2)$. +- [Shell Sort](ShellSortImple.py): Implementation of Shell Sort. Complexity: $O(n^2)$ worst case, depends on gap sequence. +- [Merge Sort](MergeSortImple.py): A recursive "divide and conquer" algorithm. Complexity: $O(n \log n)$. +- [Quick Sort](QuickSortImple.py): Implementation of Quick Sort. Complexity: $O(n \log n)$ average, $O(n^2)$ worst case. diff --git a/Stacks/README.md b/Stacks/README.md index e799a74..7bd76e3 100644 --- a/Stacks/README.md +++ b/Stacks/README.md @@ -4,5 +4,5 @@ This directory contains Python implementations of the Stack data structure and i ## Contents -- [Stack Implementation](StackImple.py): Basic implementation of a LIFO (Last-In-First-Out) stack using a Python list. Includes `push`, `pop`, `peek`, `isEmpty`, and `size` methods. -- [Balanced Parentheses Check](BalanceParenthlessCheckImple.py): Uses a stack to check if a string of opening and closing parentheses (round, square, and curly) is balanced. +- [Stack Implementation](StackImple.py): Basic implementation of a LIFO (Last-In-First-Out) stack using a Python list. Complexity: $O(1)$ for push/pop/peek. +- [Balanced Parentheses Check](BalanceParenthlessCheckImple.py): Uses a stack to check if a string of opening and closing parentheses is balanced. Complexity: $O(n)$. diff --git a/Trees/buildTreeTest.py b/Trees/BuildTreeTest.py similarity index 100% rename from Trees/buildTreeTest.py rename to Trees/BuildTreeTest.py diff --git a/Trees/README.md b/Trees/README.md index 2047225..1d1670c 100644 --- a/Trees/README.md +++ b/Trees/README.md @@ -5,19 +5,19 @@ This directory contains Python implementations of various tree-based data struct ## Contents ### Binary Search Trees (BST) -- [Binary Search Tree Implementation](BinarySearchTreesImple.py): A comprehensive implementation of a BST with `TreeNode` and `BinarySearchTree` classes, including insertion, deletion, and search. -- [Validate BST (Solution 1)](BinarySearchTreeCheckImpleSol1.py): Validates a BST by performing an in-order traversal and checking if the resulting values are sorted. -- [Validate BST (Solution 2)](BinarySearchTreeCheckImpleSol2.py): Validates a BST by keeping track of the minimum and maximum allowable values for each node. -- [Trim a BST](TrimBinarySearchTreeImple.py): Trims a BST so that all node values fall within a specified range $[min, max]$. +- [Binary Search Tree Implementation](BinarySearchTreesImple.py): A comprehensive implementation of a BST. Complexity: $O(\log n)$ average, $O(n)$ worst case. +- [Validate BST (Solution 1)](BinarySearchTreeCheckImpleSol1.py): Validates a BST using in-order traversal. Complexity: $O(n)$. +- [Validate BST (Solution 2)](BinarySearchTreeCheckImpleSol2.py): Validates a BST using range check. Complexity: $O(n)$. +- [Trim a BST](TrimBinarySearchTreeImple.py): Trims a BST to a specified range. Complexity: $O(n)$. ### Search Algorithms -- [Binary Search (Iterative)](BinarySearchImple.py): Iterative implementation of the binary search algorithm on a sorted list. -- [Binary Search (Recursive)](BinarySearchRecursiveImple.py): Recursive implementation of the binary search algorithm. +- [Binary Search (Iterative)](BinarySearchImple.py): Iterative binary search on a sorted list. Complexity: $O(\log n)$. +- [Binary Search (Recursive)](BinarySearchRecursiveImple.py): Recursive binary search. Complexity: $O(\log n)$. ### Heaps -- [Binary Heap Implementation](BinaryHeapImple.py): Implements a min-heap using a recursive approach, including `insert`, `delMin`, and `buildHeap`. +- [Binary Heap Implementation](BinaryHeapImple.py): Min-heap implementation. Complexity: $O(\log n)$ for insert/delMin, $O(n)$ for buildHeap. ### Tree Representations & Traversals -- [Nodes and References Representation](TreeRepresentationWithNodesReferences.py): A simple implementation of a binary tree using a class-based nodes and references approach. -- [List of Lists Representation](buildTreeTest.py): Demonstrates building and manipulating a tree using a "list of lists" approach. -- [Tree Level Order Print](TreeLevelOrderPrintImple.py): Prints a binary tree in level order (breadth-first) using a queue, with each level on a new line. +- [Nodes and References Representation](TreeRepresentationWithNodesReferences.py): Simple binary tree using classes. +- [List of Lists Representation](BuildTreeTest.py): Tree using a "list of lists" approach. +- [Tree Level Order Print](TreeLevelOrderPrintImple.py): Level order traversal (BFS) using a queue. Complexity: $O(n)$.