DataStructuresAndAlgorithms/Practical-C15.cpp

// WARNING: THIS CODE HAS NOT BEEN TESTED. 
// IT WILL TAKE 1-2 MONTHS TO PERFECT THE CODE. 
// IF YOU FACE ANY ERRORS, UNEXPECTED BEHAVIOUR OR HAVE ANY SUGGESTIONS, 
// LET US KNOW BY CREATING AN ISSUE ON OUR KSKA GIT REPOSITORY.

/*
Problem Statement: You have a business with several offices; you want to lease phone lines to connect them up with each other; and the phone company charges different amounts of money to connect different pairs of cities. You want a set of lines that connects all your offices with a minimum total cost. Solve the problem by suggesting appropriate data structures.

Code from Data Structures and Algorithms (SPPU - Second Year - Computer Engineering - Content) repository on KSKA Git: https://git.kska.io/sppu-se-comp-content/DataStructuresAndAlgorithms/
*/

// BEGINNING OF CODE
#include<iostream>
using namespace std;

class Office
{
    int n;
    int a[10][10];
    string office[10];

public:
    void input();
    void display();
    void Prims();
};

void Office::input()
{
    cout<<"\nEnter no. of offices: ";
    cin>>n;
    cout<<"\nEnter the names of offices: ";
    for(int i=0 ; i<n ; i++)
        cin >> office[i];

    cout<<"\nEnter the cost to connect the offices: ";
    for(int i=0 ; i<n ; i++)
        for(int j=i ; j<n ; j++)
        {
            if(i==j)
            {
                a[i][j] = 0;
                continue;
            }

            cout<<"\nEnter the cost to connect " << office[i] <<" and " << office[j]<< " : ";
            cin >> a[i][j];
            a[j][i] = a[i][j];
        }
}

void Office::display()
{

    for(int i=0 ; i<n ; i++)
    {
        cout<<"\n";
        for(int j=0 ; j<n ; j++)
        {
            cout<<a[i][j] << "\t";
        }
   }
}

void Office::Prims()
{
    int visit[n], minCost=0, count=1, minIndex, cost=0;
    for(int i=0 ; i<n ; i++)
        visit[i] = 0;

    cout<<"\n\nShortest path: ";
    visit[0]=1;
    cout<<office[0] << " -> ";
    while(1)
    {
        minCost = 10000;
        for(int i=0 ; i<n ; i++)
        {
            for(int j=0 ; j<n ; j++)
            {
                if(visit[i]==1 && a[i][j]!=0 && a[i][j]< minCost && visit[j]==0)
                {
                    minCost = a[i][j];
                    minIndex = j;
                }
            }
        }
        visit[minIndex]=1;
        cout<<office[minIndex] << " -> ";
        cost = cost + minCost;
        count++;

        if(count==n)
            break;
    }

    cout<<"\nMinimum cost: "<<cost;

}

int main()
{
    Office o1;
    int choice;
MENU:
    cout<<"\n\nMINIMUM SPANNING TREE";
    cout<<"\n1. Input data";
    cout<<"\n2. Display data";
    cout<<"\n3. Calculate minimum cost";
    cout<<"\n4. Exit";
    cout<<"\nEnter your choice: ";
    cin >> choice;
    switch(choice)
    {
    case 1:
    	o1.input();
    	break;
    case 2:
    	o1.display();
    	break;
    case 3:
    	o1.Prims();
    	break;
    case 4:
    	return 0;
    default:
    	cout<<"\nInvalid choice.Try again!";
    }
    if(choice != 5)
    	goto MENU;
    return 0;
}
// END OF CODE
// EXPERIMENTAL CODE