Add comprehensive change viewing functionality to track LeetCode solutions progress

.gitignore

@@ -0,0 +1,32 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+env/
+venv/
+.venv/
+
+# Temporary files
+*.tmp
+*.temp
+.DS_Store
+Thumbs.db
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# Build artifacts
+*.class
+*.exe
+*.o
+*.out
+a.out
+
+# Test files
+test*
+temp*

CHANGELOG.md

@@ -0,0 +1,83 @@
+# 📝 Changelog
+
+All notable changes to this LeetCode solutions repository will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+
+## 🚀 How to View Changes
+
+You can view changes in several ways:
+
+### Using the Change Viewer Script
+```bash
+# View recent changes (last 7 days)
+python3 view_changes.py
+
+# View changes from last 30 days  
+python3 view_changes.py --recent 30
+
+# Show solution statistics
+python3 view_changes.py --stats
+
+# List all solutions
+python3 view_changes.py --list
+
+# View change history for a specific file
+python3 view_changes.py --file "Solutions/121. Best Time to Buy and Sell Stock.java"
+```
+
+### Using Git Commands
+```bash
+# View recent commits
+git log --oneline -10
+
+# View changes in the last week
+git log --since="1 week ago" --oneline
+
+# View detailed changes for a specific file
+git log -p -- "Solutions/filename.java"
+
+# See what files were changed in recent commits
+git log --name-only --oneline -5
+```
+
+---
+
+## [Unreleased]
+
+### Added
+- 📜 `view_changes.py` - Interactive script to view repository changes
+- 📝 `CHANGELOG.md` - This changelog file to track all changes
+- 🔍 Enhanced documentation for viewing changes
+
+### Removed
+- 🗑️ Removed placeholder `blah` file from Solutions directory
+
+---
+
+## [2025-09-08] - Repository Enhancement
+
+### Added
+- 🖼️ Added contribution snake animation to README
+- 📚 Enhanced README with better usage instructions
+- ☕ **121. Best Time to Buy and Sell Stock** - Java solution with comments
+- 💻 **1342. Number of Steps to Reduce a Number to Zero** - C++ solution
+- 💻 **1672. Richest Customer Wealth** - C++ solution
+- 💻 **412. Fizz Buzz** - C++ solution  
+- ☕ **42. Trapping Rain Water** - Java solution with detailed logic
+
+### Changed
+- 📖 Updated README with comprehensive usage guide
+- 🎯 Added clear goals and learning objectives
+- 📬 Added contact information and social links
+
+---
+
+## Legend
+- ☕ Java solutions
+- 💻 C++ solutions  
+- 🐍 Python solutions
+- 📚 Documentation updates
+- 🔧 Tools and utilities
+- 🐛 Bug fixes
+- 🗑️ Removals

README.md

@@ -13,6 +13,25 @@ This repository contains all of my **LeetCode problem solutions**, stored in a s
 - File names usually match the problem title (underscores instead of spaces).  
 - Use the search bar on GitHub to quickly find a problem by name.  
 
+## 📈 View Changes & Track Progress
+Want to see what's new or track your progress? Use the built-in change viewer:
+
+```bash
+# View recent changes (last 7 days)
+python3 view_changes.py
+
+# View changes from last 30 days  
+python3 view_changes.py --recent 30
+
+# Show solution statistics
+python3 view_changes.py --stats
+
+# List all solutions
+python3 view_changes.py --list
+```
+
+You can also check the **`CHANGELOG.md`** file for a detailed history of all additions and updates! 📝
+
 
 ## 🛠️ Languages Used
 

view-changes.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+# LeetCode Solutions Change Viewer - Shell wrapper
+# Usage: ./view-changes.sh [options]
+
+python3 view_changes.py "$@"

view_changes.py

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+#!/usr/bin/env python3
+"""
+LeetCode Solutions Change Viewer
+Helps track and view changes to your LeetCode solutions repository.
+"""
+
+import subprocess
+import os
+import sys
+from datetime import datetime, timedelta
+import argparse
+
+def run_git_command(command):
+    """Run a git command and return the output."""
+    try:
+        result = subprocess.run(command, shell=True, capture_output=True, text=True, cwd=os.getcwd())
+        return result.stdout.strip() if result.returncode == 0 else None
+    except Exception as e:
+        print(f"Error running command: {e}")
+        return None
+
+def get_recent_changes(days=7):
+    """Get recent changes in the last N days."""
+    since_date = (datetime.now() - timedelta(days=days)).strftime('%Y-%m-%d')
+    cmd = f'git log --since="{since_date}" --pretty=format:"%h|%ad|%s" --date=short --name-only'
+    output = run_git_command(cmd)
+
+    if not output:
+        print(f"No changes found in the last {days} days.")
+        return
+
+    print(f"📅 Changes in the last {days} days:\n")
+
+    lines = output.split('\n')
+    current_commit = None
+
+    for line in lines:
+        if '|' in line:  # This is a commit line
+            parts = line.split('|')
+            hash_val, date, message = parts[0], parts[1], parts[2]
+            current_commit = hash_val
+            print(f"🔸 {date} [{hash_val}] {message}")
+        elif line.strip() and not line.startswith(' '):  # This is a file name
+            if line.startswith('Solutions/'):
+                print(f"  📝 {line}")
+            else:
+                print(f"  📄 {line}")
+    print()
+
+def get_solution_stats():
+    """Get statistics about solutions."""
+    java_count = run_git_command('find Solutions -name "*.java" | wc -l')
+    cpp_count = run_git_command('find Solutions -name "*.cpp" | wc -l')
+    py_count = run_git_command('find Solutions -name "*.py" | wc -l')
+
+    print("📊 Solution Statistics:")
+    print(f"  ☕ Java solutions: {java_count or 0}")
+    print(f"  💻 C++ solutions: {cpp_count or 0}")
+    print(f"  🐍 Python solutions: {py_count or 0}")
+    print(f"  📝 Total solutions: {int(java_count or 0) + int(cpp_count or 0) + int(py_count or 0)}")
+    print()
+
+def show_file_changes(filename):
+    """Show changes to a specific file."""
+    cmd = f'git log --follow -p -- "{filename}"'
+    output = run_git_command(cmd)
+
+    if not output:
+        print(f"No changes found for {filename}")
+        return
+
+    print(f"📜 Change history for {filename}:\n")
+    print(output)
+
+def list_solutions():
+    """List all available solutions."""
+    cmd = 'find Solutions -name "*.java" -o -name "*.cpp" -o -name "*.py" | sort'
+    output = run_git_command(cmd)
+
+    if not output:
+        print("No solutions found.")
+        return
+
+    print("📚 Available Solutions:\n")
+    for file in output.split('\n'):
+        if file.strip():
+            # Extract problem number and name from filename
+            basename = os.path.basename(file)
+            name_without_ext = os.path.splitext(basename)[0]
+            ext = os.path.splitext(basename)[1]
+
+            # Get language emoji
+            lang_emoji = "☕" if ext == ".java" else "💻" if ext == ".cpp" else "🐍"
+
+            print(f"  {lang_emoji} {name_without_ext}")
+    print()
+
+def main():
+    parser = argparse.ArgumentParser(description='View changes in your LeetCode solutions repository')
+    parser.add_argument('--recent', '-r', type=int, default=7, 
+                       help='Show changes from the last N days (default: 7)')
+    parser.add_argument('--stats', '-s', action='store_true',
+                       help='Show solution statistics')
+    parser.add_argument('--list', '-l', action='store_true',
+                       help='List all solutions')
+    parser.add_argument('--file', '-f', type=str,
+                       help='Show change history for a specific file')
+
+    args = parser.parse_args()
+
+    print("🚀 LeetCode Solutions Change Viewer\n")
+
+    # Check if we're in a git repository
+    if not run_git_command('git rev-parse --git-dir'):
+        print("❌ Error: Not in a git repository")
+        sys.exit(1)
+
+    if args.file:
+        show_file_changes(args.file)
+    elif args.list:
+        list_solutions()
+    elif args.stats:
+        get_solution_stats()
+    else:
+        get_recent_changes(args.recent)
+        get_solution_stats()
+
+if __name__ == "__main__":
+    main()