Graph Shamsur Rahman

#include <bits/stdc++.h>
using namespace std;

#define White 0
#define Gray 2
#define Black 3

int row, col;
int **graph;

class Graph
{
private:
    bool** adjacencyMatrix;
    int vertexCount;
public:

    Graph(int vertexCount)
    {

        this->vertexCount = vertexCount;
        adjacencyMatrix = new bool*[vertexCount];

        for (int i = 0; i < vertexCount; i++)
        {
            adjacencyMatrix[i] = new bool[vertexCount];
            for (int j = 0; j < vertexCount; j++)
                adjacencyMatrix[i][j] = false;
        }
    }

    Graph(const char* filename, int vertexCount)
    {

        this->vertexCount = vertexCount;
        adjacencyMatrix = new bool*[vertexCount];

        ifstream file;
        file.open(filename, ios::in);

        if( !file)
        {
            cout << "\nError: Cannot open file\n";
            return;
        }

        if(file.is_open())
        {
            for (int i = 0; i < vertexCount; i++)
            {

                adjacencyMatrix[i] = new bool[vertexCount];

                for (int j = 0; j < vertexCount; j++)
                    file>>adjacencyMatrix[i][j];
            }
        }
    }


    ~Graph()
    {
        for (int i = 0; i < vertexCount; i++)
            delete[] adjacencyMatrix[i];
        delete[] adjacencyMatrix;
    }

    void runDFS(int u, int state[])
    {

        state[u] = Gray;

        for (int v = 0; v < vertexCount; v++)

            if (isEdge(u, v) && state[v] == White)

                runDFS(v, state);

        state[u] = Black;
        cout<<u<<",";
    }

    void DFS()
    {

        int *state = new int[vertexCount];

        for (int i = 0; i < vertexCount; i++)
            state[i] = White;

        runDFS(0, state);

        delete [] state;

    }

    void display()
    {
        int u,v;

        for(u=0; u<vertexCount; ++u)
        {
            cout << "\nadj[" << (char) (u+65) << "] -> ";
            for(v=0; v<vertexCount; ++v)
            {
                cout << " " << adjacencyMatrix[u][v];
            }
        }
        cout << "\n\n";
    }

    void writeFile()
    {
        FILE *p;
        p = fopen("graph.txt", "w+");
        int u,v;

        for(u=0; u<vertexCount; ++u)
        {
            for(v=0; v<vertexCount; ++v)
            {
                fprintf(p, "%d ",  adjacencyMatrix[u][v]);
            }
            fprintf(p, "\n");
        }
        fclose(p);
    }

    bool isEdge(int i, int j)
    {
        if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount)
            return adjacencyMatrix[i][j];
        else
            return false;
    }

    void removeEdge(int i, int j)
    {
        if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount)
        {
            adjacencyMatrix[i][j] = false;
            adjacencyMatrix[j][i] = false;
        }
    }

    void addEdge(int i, int j)
    {
        if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount)
        {
            adjacencyMatrix[i][j] = true;
            adjacencyMatrix[j][i] = true;
        }
    }
};


int main()
{
    graph = new int*[row];
    for (int i = 0; i < row; i++)
    {
        graph[i] = new int[col];
    }

    for (int i = 0; i < row; i++)
    {
        for (int j = 0; j < col; j++)
        {
            graph[i][j] = 0;
        }
    }


    Graph* A = new Graph(5);

    printf("Task 1:\n");

    A->addEdge(0,3);
    A->addEdge(1,3);
    A->addEdge(1,4);
    A->addEdge(2,4);
    A->addEdge(3,0);
    A->addEdge(3,1);
    A->addEdge(3,4);
    A->addEdge(4,1);
    A->addEdge(4,2);
    A->addEdge(4,3);

    A->display();

    printf("Task 2:\n");

    A->writeFile();

    printf("\nA file named graph.txt is generated\n");

    printf("\nFinal task:\n\nReading the graph.txt file:\n\n");

    Graph* B = new Graph("graph.txt", 5);

    B->display();

    return 0;

}