feat: added graph analyser

[ADARSHsri2004]

Description

This pull request adds the C++ Graph Analyzer, a fully object-oriented tool for analyzing graph structures and computing various graph properties.

The system enables users to input graphs (directed/undirected, weighted/unweighted) and performs an in-depth analysis including cycle detection, shortest paths, connectivity, and calculation of multiple metrics like degree, density, diameter, radius, eccentricity, and centrality.

All functionalities are implemented using Object-Oriented Programming (OOP) principles for modularity, maintainability, and scalability.

Features Implemented

• Input handling for adjacency list and edge list formats
• Cycle detection
• Shortest path computation (Dijkstra / Floyd–Warshall)
• Connectivity check (BFS / DFS)
• Computation of:
  • Vertex degrees
  • Number of connected components
  • Graph density
  • Graph diameter and radius
  • Eccentricity, centrality, and reachability
• Console-based reporting of results
• Proper input validation and error handling

Design Highlights

• Modular class-based design (Graph, Vertex, Edge, Analyzer)
• Clean and maintainable codebase
• Efficient algorithms optimized for large graphs
• Well-documented methods and classes

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Semver Changes

• Patch (bug fix, no new features)
• Minor (new features, no breaking changes)
• Major (breaking changes)

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Issues

Closes: #21

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Checklist

• I have read the Contributing Guidelines