GroupC_Practical13b.cpp

/*
Experiment 13 : Represent a given grapg using adjacency matrix/list to perform DFS and using adjacency list to perform BFS. 
                Use the map of the area around the college as a graph. Identify the prominent land marks as nodes and perform DFS and BFS on that.
Adjecency List
*/

#include <iostream>
using namespace std;
#define MAX 10
#define TRUE 1
#define FALSE 0

// declaring an adjacency list for storing the graph
class lgra
{
private:
    struct node1
    {
        int vertex;
        struct node1 *next;
    };
    node1 *head[MAX];
    int visited[MAX];

public:
    //static int nodecount;
    lgra();
    void create();
    void dfs(int);
};

//constructor
lgra::lgra()
{
    int v1;
    for (v1 = 0; v1 < MAX; v1++)
        visited[v1] = FALSE;
    for (v1 = 0; v1 < MAX; v1++)
        head[v1] = NULL;
}

void lgra::create()
{
    int v1, v2;
    char ans;
    node1 *N, *first;
    cout << "Enter the vertices no. beginning with 0 : ";
    do
    {
        cout << "\nEnter the Edge of a graph : \n";
        cin >> v1 >> v2;
        if (v1 >= MAX || v2 >= MAX)
            cout << "Invalid Vertex Value!!\n";
        else
        {
            //creating link from v1 to v2
            N = new node1;
            if (N == NULL)
                cout << "Insufficient Memory!!\n";
            N->vertex = v2;
            N->next = NULL;
            first = head[v1];
            if (first == NULL)
                head[v1] = N;
            else
            {
                while (first->next != NULL)
                    first = first->next;
                first->next = N;
            }
            //creating link from v2 to v1
            N = new node1;
            if (N == NULL)
                cout << "Insufficient Memory!!\n";
            N->vertex = v1;
            N->next = NULL;
            first = head[v2];
            if (first == NULL)
                head[v2] = N;
            else
            {
                while (first->next != NULL)
                    first = first->next;
                first->next = N;
            }
        }
        cout << "\n Want to add more edges?(y/n) : ";
        cin >> ans;
    } while (ans == 'y');
}

//dfs function
void lgra::dfs(int v1)
{
    node1 *first;
    cout << endl
         << v1;
    visited[v1] = TRUE;
    first = head[v1];
    while (first != NULL)
        if (visited[first->vertex] == FALSE)
            dfs(first->vertex);
        else
            first = first->next;
}

int main()
{
    int v1;
    lgra g;
    
    g.create();
    cout << endl << "Enter the vertex from where you want to traverse : ";
    cin >> v1;
    if (v1 >= MAX)
        cout << "Invalid Vertex!!\n";
    else
    {
        cout << "The Dfs of the graph : ";
        g.dfs(v1);
    }
    
    return 0;
}