Dijkstra_array/dijkstra_array.cpp at master · divyaa2809/Dijkstra_array · GitHub

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#include <climits>
#include <iostream>
#include<stdlib.h>
#define MAX 100
#define v 100
using namespace std;
int flag;
struct node
{
    bool includeset;
    int finaldist;
    int pred;

};
struct node nodearray[v];
/*int dijkstra(int * ,int ,int);
int initialize_single_source(struct node *,int,int);
int extract_min(struct node * ,int);*/
int initialize_single_source(struct node nodearray[],int source,int vertices)
{

    for(int i=0; i<vertices; i++)
    {
        nodearray[i].includeset=false;
        nodearray[i].pred=INT_MIN;
        nodearray[i].finaldist=INT_MAX;


    }


    flag=vertices;
    nodearray[source].pred=-1;
    nodearray[source].finaldist=0;
    return flag;

}
int extract_min(struct node nodearray[],int vertices)
{
    int mindist, x;
    for(x=0;x<vertices;x++){
    if(nodearray[x].includeset==false)
    {
        break;
    }
    }
     mindist=x;
    for(int i=x+1;i<vertices;i++){
        if(nodearray[i].includeset==false && nodearray[i].finaldist<nodearray[mindist].finaldist)
        {
            mindist=i;
        }


    }
return mindist;

}


void  dijkstra(int arrk[v][v],int source,int vertices)
{
    flag=initialize_single_source(nodearray,source,vertices);
    int count = 0;

    while( flag!=0)
    {
        int p=extract_min(nodearray,vertices);

        nodearray[p].includeset=true;
        flag--;
        count++;
        for(int j=1;j<vertices;j++)
        {

            if(arrk[p][j]!=0)
            {

                if(nodearray[j].finaldist> nodearray[p].finaldist + arrk[p][j])
                {

                  nodearray[j].finaldist = nodearray[p].finaldist + arrk[p][j];
                    nodearray[j].pred = p;

                }
            }

        }
    }

    cout<<"vertex"<<"\t\t\t"<<"Minimum distance"<<endl;

for(int i=0;i<vertices;i++)
{
    cout<<i<<"\t\t\t";
    cout<<nodearray[i].finaldist<<endl;

}

}


int main()
{

    int i=0;

 int so;

    int vp;

    int arrk[MAX][MAX],e;
    cout<<"enter the number of vertices(undirected graph)"<<endl;
    cin>>vp;
    cout<<"enter the number of edges"<<endl;
    cin>>e;
    if(vp<=0 || e<=0)
    {
        cout<<"\ninvalid input";
        return 0;
    }
    for(int i=0; i<vp; i++)
    {
        for(int j=0; j<vp; j++)
        {
            if(i!=j){
            cout<<"Enter the edge length between "<<i<<" and "<<j<<" ";
            cin>>arrk[i][j];}
            else arrk[i][j]=0;

        }
    }

    cout<<"output matrix is ---->"<<endl;
    for(i=0; i<vp; i++)
    {
        for(int j=0; j<vp; j++)
        {

            cout<<"\t"<<arrk[i][j];

        }
        cout<<endl;
    }

    cout<<"enter source";
    cin>>so;

    dijkstra(arrk,so,vp);


    return 0;
}