Graph++ – Graphs in a Nutshell 🕸️

Graph++ is a C++ library that provides a full‑featured toolbox for graph analysis and exploration. It ships with three main components: the core library, a graphical user‑interface (GUI) application, and a unit‑test suite. It is designed to help researchers, students and graph enthusiasts work efficiently with graphs (degree calculation, chromatic numbers, Hamiltonian/Eulerian paths, etc.).

This project was initially developed on Gitlab. Pipelines remain in the Gitlab format.

Project Structure

The repository is organized into three top‑level modules:

Module	Purpose
Library	C++ library (graph.h, implementations, data structures, algorithms). Provides a clean API for creating, modifying and analyzing graphs.
Application	Desktop GUI application (Windows 64‑bit) that builds on the library. Offers visual editing, layout customisation, interactive property display and algorithm execution using Qt.
Tests	Unit‑test suite exercising the library’s functionality.

Usage (C++ Library)

Below is a minimal example showing how to create a circular graph, query basic properties and run a few algorithms. The main concept of Graph++ is that you are free to define the data type of the graph nodes. Graph++ uses templates to provide the user with the possibility of building graphs of integers, floats, or more complex data structures. In the examples below, a graph of integers is used.

#include <graph.h>

    ///.......
    // Create some vertices
    int vertices[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

    // Create a graph for those vertices
    Graph<int>* graph = new Graph<int>();

    // Add the vertices to the graph
    for(int i : vertices){
        graph->addVertex(&i);
    }

    // Add some edges to the graph (Circular graph)
    for(int i : vertices){
        int nextIndex = i + 1;
        if(nextIndex >= nbVertices){
            nextIndex = 0;
        }
        graph->addDoubleEdge(&vertices[i], &vertices[nextIndex]);
    }

    // Basic properties
    std::cout << graph->getNbVertices() << std::endl;
    std::cout << graph->getNbEdges() << std::endl;
    std::cout << graph->isOriented() << std::endl;
    std::cout << graph->isWeighted() << std::endl;

    // Algorithms
    Graph<int>* hamiltionianPath = graph->getHamiltonianPath();
    Graph<int>* shortestPathGraph = graph->getMinimumDistanceGraph(&vertices[3]);
    Graph<int>* minimumSpanningTree = graph->getMinimumSpanningTree();

License

The software was developed by Damien Tschan, Jonas Flückiger, and Simon Plumey, all rights reserved.