LeetCode Solutions

This repository contains my solutions to various LeetCode problems implemented in C++ and Python.

Repository Structure

The repository is organized as follows:

• Each problem solution is contained in a single file named probX.cpp or probX.py, where X is the problem number
• Solutions include detailed problem descriptions, examples, and constraints
• Code is well-commented with explanations of the algorithms and approaches used
• Multiple solution approaches are provided where applicable

Problems Solved

Statistics

• Total Problems: 37
• C++ Solutions: 12
• Python Solutions: 25
• Easy: 34 problems
• Medium: 2 problems
• Hard: 1 problem

Problem List

#	Difficulty	Problem	Language	Solution
1	Easy	Two Sum	C++	prob1.cpp
2	Medium	Add Two Numbers	C++	prob2.cpp
3	Medium	Longest Substring Without Repeating Characters	C++	prob3.cpp
4	Hard	Median of Two Sorted Arrays	C++	prob4.cpp
5	Medium	Longest Palindromic Substring	C++	prob5.cpp
9	Easy	Palindrome Number	C++	prob9.cpp
13	Easy	Roman to Integer	C++	prob13.cpp
14	Easy	Longest Common Prefix	C++	prob14.cpp
20	Easy	Valid Parentheses	Python	prob20.py
21	Easy	Merge Two Sorted Lists	C++	prob21.cpp
26	Easy	Remove Duplicates from Sorted Array	Python	prob26.py
27	Easy	Remove Element	Python	prob27.py
28	Easy	Find the Index of the First Occurrence in a String	Python	prob28.py
35	Easy	Search Insert Position	Python	prob35.py
58	Easy	Length of Last Word	Python	prob58.py
66	Easy	Plus One	Python	prob66.py
67	Easy	Add Binary	Python	prob67.py
69	Easy	Sqrt(x)	Python	prob69.py
70	Easy	Climbing Stairs	Python	prob70.py
83	Easy	Remove Duplicates from Sorted List	Python	prob83.py
88	Easy	Merge Sorted Array	C++	prob88.cpp
94	Easy	Binary Tree Inorder Traversal	Python	prob94.py
100	Easy	Same Tree	Python	prob100.py
101	Easy	Symmetric Tree	Python	prob101.py
104	Easy	Maximum Depth of Binary Tree	Python	prob104.py
108	Easy	Convert Sorted Array to Binary Search Tree	Python	prob108.py
110	Easy	Balanced Binary Tree	Python	prob110.py
111	Easy	Minimum Depth of Binary Tree	Python	prob111.py
112	Easy	Path Sum	Python	prob112.py
118	Easy	Pascal's Triangle	Python	prob118.py
119	Easy	Pascal's Triangle II	Python	prob119.py
121	Easy	Best Time to Buy and Sell Stock	Python	prob121.py
125	Easy	Valid Palindrome	Python	prob125.py
136	Easy	Single Number	Python	prob136.py
175	Easy	Combine Two Tables	Python	prob175.py
176	Easy	Second Highest Salary	Python	prob176.py
177	Easy	Nth Highest Salary	Python	prob177.py
178	Easy	Rank Scores	Python	prob178.py
386	Medium	Lexicographical Numbers	C++	prob386.cpp
632	Hard	Smallest Range Covering Elements from K Lists	C++	prob632.cpp

Technologies Used

• C++: Core algorithms, data structures, and system-level optimizations
• Python: Rapid prototyping, clean and readable solutions
• Git: Version control and project management

Setup and Execution

Prerequisites

• For C++ solutions:
  • C++ compiler (GCC or Clang recommended)
  • C++11 or later standard support
• For Python solutions:
  • Python 3.x interpreter
• Optional: Visual Studio Code or any preferred IDE

Running C++ Solutions

# Navigate to the repository
cd /path/to/Leetcode

# Compile a specific C++ solution (using GCC)
g++ -g probX.cpp -o probX

# Run the solution
./probX

Running Python Solutions

# Navigate to the repository
cd /path/to/Leetcode

# Run a specific Python solution
python3 probX.py

# Or with explicit Python version
python probX.py

Code Structure

Each solution file typically includes:

1. Problem description with LeetCode URL reference
2. Difficulty level (Easy/Medium/Hard)
3. Detailed algorithm explanation and approach analysis
4. Time and space complexity comments
5. Multiple solution implementations (where applicable)
6. Well-commented code with clear variable names and logic flow

Problem Categories

Data Structures

• Arrays and Strings
• Linked Lists
• Binary Trees
• Hash Maps/Tables
• Stacks

Algorithms

• Two Pointers
• Sliding Window
• Dynamic Programming
• Tree Traversal (DFS/BFS)
• Binary Search
• Sorting and Searching

Database (SQL)

• Table Joins
• Ranking Functions
• Aggregation Queries

Learning Progress

This repository represents my journey through algorithmic problem-solving, showcasing:

• Progressive difficulty: Starting with easy problems and advancing to harder challenges
• Language diversity: Solutions in both C++ and Python to leverage each language's strengths
• Multiple approaches: Different algorithms and optimizations for the same problem
• Best practices: Clean, readable, and well-documented code

Contributing

Feel free to:

• Suggest improvements or alternative solutions
• Report bugs or issues
• Propose optimizations
• Add test cases

Submit contributions through issues or pull requests!