From 780b580e08fc5997f245b8f7de6641488650a4b2 Mon Sep 17 00:00:00 2001
From: Rohithmohan255 <44532562+Rohithmohan255@users.noreply.github.com>
Date: Sun, 28 Oct 2018 06:47:21 +0530
Subject: [PATCH] dijkstra's algorithm implemented

---
 dijkstra.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 dijkstra.cpp

diff --git a/dijkstra.cpp b/dijkstra.cpp
new file mode 100644
index 0000000..6898ab7
--- /dev/null
+++ b/dijkstra.cpp
@@ -0,0 +1,52 @@
+#include<iostream>
+#include<climits>     /*Used for INT_MAX*/
+using namespace std;
+#define vertex 7      /*It is the total no of verteices in the graph*/
+int minimumDist(int dist[], bool Dset[])   /*A method to find the vertex with minimum distance which is not yet included in Dset*/
+{
+	int min=INT_MAX,index;                 /*initialize min with the maximum possible value as infinity does not exist */
+	for(int v=0;v<vertex;v++)
+	{
+		if(Dset[v]==false && dist[v]<=min)      
+		{
+			min=dist[v];
+			index=v;
+		}
+	}
+	return index;
+}
+void dijkstra(int graph[vertex][vertex],int src) /*Method to implement shortest path algorithm*/
+{
+	int dist[vertex];                             
+	bool Dset[vertex];
+	for(int i=0;i<vertex;i++)                    /*Initialize distance of all the vertex to INFINITY and Dset as false*/  
+	{
+		dist[i]=INT_MAX;
+		Dset[i]=false;	
+	}
+	dist[src]=0;                                   /*Initialize the distance of the source vertec to zero*/
+	for(int c=0;c<vertex;c++)                           
+	{
+		int u=minimumDist(dist,Dset);              /*u is any vertex that is not yet included in Dset and has minimum distance*/
+		Dset[u]=true;                              /*If the vertex with minimum distance found include it to Dset*/ 
+		for(int v=0;v<vertex;v++)                  
+		/*Update dist[v] if not in Dset and their is a path from src to v through u that has distance minimum than current value of dist[v]*/
+		{
+			if(!Dset[v] && graph[u][v] && dist[u]!=INT_MAX && dist[u]+graph[u][v]<dist[v])
+			dist[v]=dist[u]+graph[u][v];
+		}
+	}
+	cout<<"Vertex\t\tDistance from source"<<endl;
+	for(int i=0;i<vertex;i++)                       /*will print the vertex with their distance from the source to the console */
+	{
+		char c=65+i;
+		cout<<c<<"\t\t"<<dist[i]<<endl;
+	}
+}
+int main()
+{
+	int graph[vertex][vertex]={{0,5,3,0,0,0,0},{0,0,2,0,3,0,1},{0,0,0,7,7,0,0},{2,0,0,0,0,6,0},{0,0,0,2,0,1,0},{0,0,0,0,0,0,0},
+		                        {0,0,0,0,1,0,0}};
+	dijkstra(graph,0);
+	return 0;	                        
+}
\ No newline at end of file