From 739dbdc598b1605615245e7fd20c0b9ce1eb6e38 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 25 Mar 2026 01:42:46 +0000
Subject: [PATCH] Add sub-directory READMEs, update root README, and add
 LICENSE

- Created localized README.md files for all 10 sub-directories (Arrays, Error-debug, GraphAlgorithms, LinkedLists, Queues, Recursion, Sorting, Stacks, Trees, and deque).
- Updated the root README.md to include 'Trees/buildTreeTest.py'.
- Added an MIT LICENSE file as mentioned in the project documentation.

Co-authored-by: ppant <149585+ppant@users.noreply.github.com>
---
 Arrays/README.md          | 17 +++++++++++++++++
 Error-debug/README.md     |  9 +++++++++
 GraphAlgorithms/README.md | 18 ++++++++++++++++++
 LICENSE                   | 21 +++++++++++++++++++++
 LinkedLists/README.md     | 25 +++++++++++++++++++++++++
 Queues/README.md          | 13 +++++++++++++
 README.md                 |  4 ++++
 Recursion/README.md       | 33 +++++++++++++++++++++++++++++++++
 Sorting/README.md         | 29 +++++++++++++++++++++++++++++
 Stacks/README.md          | 13 +++++++++++++
 Trees/README.md           | 35 +++++++++++++++++++++++++++++++++++
 deque/README.md           |  9 +++++++++
 12 files changed, 226 insertions(+)
 create mode 100644 Arrays/README.md
 create mode 100644 Error-debug/README.md
 create mode 100644 GraphAlgorithms/README.md
 create mode 100644 LICENSE
 create mode 100644 LinkedLists/README.md
 create mode 100644 Queues/README.md
 create mode 100644 Recursion/README.md
 create mode 100644 Sorting/README.md
 create mode 100644 Stacks/README.md
 create mode 100644 Trees/README.md
 create mode 100644 deque/README.md

diff --git a/Arrays/README.md b/Arrays/README.md
new file mode 100644
index 0000000..76a37f4
--- /dev/null
+++ b/Arrays/README.md
@@ -0,0 +1,17 @@
+# Arrays
+
+This directory contains implementations of various array-related algorithms.
+
+## Contents
+
+### Anagram Check
+Checks if two strings are anagrams of each other.
+- **Files**: `Anagram_Check_Sorted_Sol.py`, `Anagram_Check_manual_Sol.py`
+
+### Array Pair Sum
+Given an integer array, output all unique pairs that sum up to a specific value `k`.
+- **File**: `ArrayPairSumSol.py`
+
+### Find Missing Element
+Find the missing element in a shuffled second array.
+- **Files**: `ArrayFindTheMissingElement_XOR_sol.py`, `ArrayFindTheMissingElement_brute_force_sol.py`, `ArrayFindTheMissingElement_hash_table_sol.py`, `ArrayFindTheMissingElement_takingSumandSubtract_sol.py`
diff --git a/Error-debug/README.md b/Error-debug/README.md
new file mode 100644
index 0000000..7a209f6
--- /dev/null
+++ b/Error-debug/README.md
@@ -0,0 +1,9 @@
+# Error Handling
+
+This directory contains examples of error handling and debugging in Python.
+
+## Contents
+
+### Basic Exception Handling
+Demonstrates `try-except-else-finally` blocks and user input validation.
+- **File**: `ErrorExceptions.py`
diff --git a/GraphAlgorithms/README.md b/GraphAlgorithms/README.md
new file mode 100644
index 0000000..fc993ac
--- /dev/null
+++ b/GraphAlgorithms/README.md
@@ -0,0 +1,18 @@
+# Graph Algorithms
+
+This directory contains implementations of various graph-related algorithms.
+
+## Contents
+
+### Adjacency List Implementation
+- **File**: `AdjacencyListGraphImple.py`
+
+### Breadth First Search (BFS) - Word Ladder Problem
+- **Files**: `BFS.py`, `WordLadderProblem.py`
+
+### Depth First Search (DFS) - Knight's Tour Problem
+- **Files**: `DFSImpleTheKnightsTourProblem.py`, `TheKnightsTourProblem.py`
+
+### General DFS
+A more general implementation of Depth First Search.
+- **File**: `DFSGeneral.py`
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..cecd15e
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 Pradeep K. Pant
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/LinkedLists/README.md b/LinkedLists/README.md
new file mode 100644
index 0000000..8cf6b73
--- /dev/null
+++ b/LinkedLists/README.md
@@ -0,0 +1,25 @@
+# Linked Lists
+
+This directory contains implementations of various linked list structures and algorithms.
+
+## Contents
+
+### Singly Linked List Implementation
+Basic skeleton for a Singly Linked List.
+- **File**: `SingleLinkedListImple.py`
+
+### Doubly Linked List Implementation
+Basic skeleton for a Doubly Linked List.
+- **File**: `DoublyLinkedListImple.py`
+
+### Singly Linked List Cycle Check
+Check if a singly linked list contains a cycle using the "two runners" (slow and fast pointers) strategy.
+- **File**: `SinglyLinkedListCycleCheckImple.py`
+
+### Reverse a Linked List
+Reverse a linked list in-place.
+- **File**: `LinkedListReversal.py`
+
+### Nth to Last Node
+Find the nth to last node in a linked list.
+- **File**: `LinkedListNthToLastNode.py`
diff --git a/Queues/README.md b/Queues/README.md
new file mode 100644
index 0000000..98b56fe
--- /dev/null
+++ b/Queues/README.md
@@ -0,0 +1,13 @@
+# Queues
+
+This directory contains implementations of queue data structures.
+
+## Contents
+
+### Queue Implementation
+Basic queue operations (FIFO): `enqueue`, `dequeue`, `isEmpty`, `size`.
+- **File**: `QueueImple.py`
+
+### Queue with Two Stacks
+Implement a queue using two stacks.
+- **File**: `QueueWith2StacksImple.py`
diff --git a/README.md b/README.md
index 790acf4..5dcd3e7 100644
--- a/README.md
+++ b/README.md
@@ -149,6 +149,10 @@ Implementing a tree using classes and references.
 Print a binary tree in level order.
 - **File**: `Trees/TreeLevelOrderPrintImple.py`
 
+### Build Tree Test
+Build a tree and fetch nodes and insert using list of lists.
+- **File**: `Trees/buildTreeTest.py`
+
 ---
 
 ## Sorting
diff --git a/Recursion/README.md b/Recursion/README.md
new file mode 100644
index 0000000..f99b078
--- /dev/null
+++ b/Recursion/README.md
@@ -0,0 +1,33 @@
+# Recursion
+
+This directory contains various examples of recursive algorithms.
+
+## Contents
+
+### Cumulative Sum
+Compute the cumulative sum from 0 to `n`.
+- **File**: `RecursionCumulativeSum.py`
+
+### Sum of Digits
+Returns the sum of all individual digits in an integer.
+- **File**: `RecursionSumOfDigits.py`
+
+### Word Split
+Determine if a string can be split into words found in a given list.
+- **File**: `RecursionWordSplit.py`
+
+### Reverse a String
+Recursive implementation to reverse a string.
+- **File**: `RecursionReverseStr.py`
+
+### String Permutations
+Output all possible permutations of a string.
+- **File**: `RecursionStrPermutation.py`
+
+### Fibonacci Sequence
+Implementations using iteration, recursion, and dynamic programming (memoization).
+- **Files**: `FibonacciSeqIterative.py`, `FibonacciSeqRecursion.py`, `FibonacciSeqDynamic.py`
+
+### Coin Change Problem
+Find the fewest coins needed to make a change amount.
+- **Files**: `CoinChangeProblemRecursion.py`, `CoinChangeProblemDynamic.py`
diff --git a/Sorting/README.md b/Sorting/README.md
new file mode 100644
index 0000000..3948aa6
--- /dev/null
+++ b/Sorting/README.md
@@ -0,0 +1,29 @@
+# Sorting Algorithms
+
+This directory contains implementations of various sorting algorithms.
+
+## Contents
+
+### Bubble Sort
+- **File**: `BubbleSortImple.py`
+- **Complexity**: $O(n^2)$ worst and average case, $O(n)$ best case.
+
+### Selection Sort
+- **File**: `SelectionSortImple.py`
+- **Complexity**: $O(n^2)$ for all cases.
+
+### Insertion Sort
+- **File**: `InsertionSortImple.py`
+- **Complexity**: $O(n^2)$ worst and average case, $O(n)$ best case.
+
+### Merge Sort
+- **File**: `MergeSortImple.py`
+- **Complexity**: $O(n \log n)$ for all cases.
+
+### Quick Sort
+- **File**: `QuickSortImple.py`
+- **Complexity**: $O(n^2)$ worst case, $O(n \log n)$ average/best case.
+
+### Shell Sort
+- **File**: `ShellSortImple.py`
+- **Complexity**: Between $O(n)$ and $O(n^2)$ depending on increment sequence.
diff --git a/Stacks/README.md b/Stacks/README.md
new file mode 100644
index 0000000..f8fbaea
--- /dev/null
+++ b/Stacks/README.md
@@ -0,0 +1,13 @@
+# Stacks
+
+This directory contains implementations of stack data structures and related algorithms.
+
+## Contents
+
+### Stack Implementation
+Basic stack operations (LIFO): `push`, `pop`, `peek`, `isEmpty`, `size`.
+- **File**: `StackImple.py`
+
+### Balanced Parentheses Check
+Check if a string of opening and closing parentheses is balanced.
+- **File**: `BalanceParenthlessCheckImple.py`
diff --git a/Trees/README.md b/Trees/README.md
new file mode 100644
index 0000000..7c186f3
--- /dev/null
+++ b/Trees/README.md
@@ -0,0 +1,35 @@
+# Trees
+
+This directory contains implementations of various tree structures and related algorithms.
+
+## Contents
+
+### Binary Search Tree Implementation
+- **File**: `BinarySearchTreesImple.py`
+
+### Binary Heap Implementation
+- **File**: `BinaryHeapImple.py`
+
+### Binary Search
+Recursive and iterative implementations.
+- **Files**: `BinarySearchImple.py`, `BinarySearchRecursiveImple.py`
+
+### Validate BST
+Check if a binary tree is a valid Binary Search Tree.
+- **Files**: `BinarySearchTreeCheckImpleSol1.py`, `BinarySearchTreeCheckImpleSol2.py`
+
+### Trim a BST
+Trim a BST so all nodes are within a given range `[min, max]`.
+- **File**: `TrimBinarySearchTreeImple.py`
+
+### Tree Representation (Nodes & References)
+Implementing a tree using classes and references.
+- **File**: `TreeRepresentationWithNodesReferences.py`
+
+### Tree Level Order Print
+Print a binary tree in level order.
+- **File**: `TreeLevelOrderPrintImple.py`
+
+### Build Tree Test
+Build a tree and fetch nodes and insert using list of lists.
+- **File**: `buildTreeTest.py`
diff --git a/deque/README.md b/deque/README.md
new file mode 100644
index 0000000..70cc1d4
--- /dev/null
+++ b/deque/README.md
@@ -0,0 +1,9 @@
+# Deque
+
+This directory contains implementations of deque data structures.
+
+## Contents
+
+### Deque Implementation
+Double-ended queue operations: `addFront`, `addRear`, `removeFront`, `removeRear`, `isEmpty`, `size`.
+- **File**: `DequeImple.py`