Create dijkstra'sAlgo.cpp

dijkstra'sAlgo.cpp

@@ -0,0 +1,86 @@
+
+  // Graph - Dijkstra's Algorithm
+
+#include<bits/stdc++.h>
+#include<algorithm>
+#include<iostream>
+using namespace std;
+#define INF 0x3f3f3f3f  
+
+class Graph
+{
+    int V; 
+    list<pair<int,int>>*adj; 
+public :
+    Graph(int V); //constructor
+    void addEdge(int u,int v,int wt);
+    void ShortestPath(int source);
+};
+Graph::Graph(int V)
+{
+    this->V=V;
+    adj=new list< pair<int,int> >[V];
+}
+void Graph::addEdge(int u,int v,int wt)
+{
+    adj[u].push_back(make_pair(v,wt));
+    adj[v].push_back(make_pair(u,wt));
+}
+void Graph::ShortestPath(int source)
+{
+  vector<int> dist(V,INF); 
+
+  set<pair<int,int>> setds;  
+
+  setds.insert(make_pair(0,source)); 
+  dist[source]=0; 
+
+  while(!setds.empty())
+  {
+     pair<int,int> temp=*(setds.begin()); 
+     setds.erase(setds.begin());   
+
+     int u=temp.second; 
+     list<pair<int,int>>::iterator i;
+     for(i=adj[u].begin();i!=adj[u].end();i++)
+     {
+         int v=(*i).first; 
+         int weight=(*i).second; 
+
+         if(dist[v]>dist[u]+weight) 
+         {
+             if(dist[v]!=INF)
+                setds.erase(setds.find(make_pair(dist[v],v))); 
+            dist[v]=dist[u]+weight;
+            setds.insert(make_pair(dist[v],v)); 
+         }
+     }
+  }
+  cout<<"Vertex   distance from Source :\n";
+  for(int i=0;i<V;i++)
+   // cout<<"   "<<i<<"           "<<dist[i]<<"\n";
+   printf(" %d \t\t %d\n",i,dist[i]);
+}
+int main()
+{
+    int V=9;
+    Graph g(V);
+
+    g.addEdge(0,1,4);
+    g.addEdge(0,7,8);
+    g.addEdge(1,2,8);
+    g.addEdge(7,6,1);
+    g.addEdge(7,8,7);
+    g.addEdge(2,8,2);
+    g.addEdge(8,6,6);
+    g.addEdge(2,3,7);
+    g.addEdge(2,5,4);
+    g.addEdge(6,5,2);
+    g.addEdge(3,5,14);
+    g.addEdge(3,4,9);
+    g.addEdge(5,4,10);
+
+    g.ShortestPath(0);
+
+    return 0;
+}