Merge pull request #189 from adarsh115/master

added dijkstra algorithm in cpp

Dijkstra Shortest Path/dijkstra.cpp

@@ -0,0 +1,79 @@
+
+#include<bits/stdc++.h>
+using namespace std;
+// Total number of vertices in graph
+const V = 9;  
+
+// For printing the shortest path
+int shortest_path(int dist[], int n)
+{
+   cout<<"Vertex "<<"\t"<<"Distance from Source\n";
+   for (int i = 0; i < V; i++)
+   cout<<" \t\t \n"<< i<<" \t\t "<<dist[i];
+}
+
+// For calculating minimum distance
+int minDist(int dist[], bool Set[])
+{
+   int min = INT_MAX, min_index;
+   for (int i = 0; i < V; i++)
+   if (Set[i] == false && dist[i] <= min)
+   min = dist[i], min_index = i;
+   return min_index;
+}
+
+// Calculate shortest paths from source to all other vertices
+void Dijkstra(int g[V][V], int src)
+{
+   int dist[V];
+   bool Set[V];
+   for (int i = 0; i < V; i++)
+   dist[i] = INT_MAX, Set[i] = false;
+   dist[src] = 0;
+   for (int c = 0; c < V- 1; c++)
+   {
+      int u = minDist(dist, Set);
+      Set[u] = true;
+      for (int j = 0; j < V; j++)
+    if (!Set[j] && g[u][j] && dist[u] != INT_MAX && dist[u]+ g[u][j] < dist[j])
+    {
+    dist[j] = dist[u] + g[u][j];
+      }
+   }
+   shortest_path(dist, V);
+}
+
+
+//DIJKSTRA
+int main()
+{
+      ios_base::sync_with_stdio(false);
+      cin.tie(NULL);
+
+//       int G[V][V] = { 
+//       { 0, 4, 0, 0, 0, 0, 0, 8, 0 },
+//       { 4, 0, 8, 0, 0, 0, 0, 11, 0 },
+//       { 0, 8, 0, 7, 0, 4, 0, 0, 2 },
+//       { 0, 0, 7, 0, 9, 14, 0, 0, 0 },
+//       { 0, 0, 0, 9, 0, 10, 0, 0, 0 },
+//       { 0, 0, 4, 14, 10, 0, 2, 0, 0 },
+//       { 0, 0, 0, 0, 0, 2, 0, 1, 6 },
+//       { 8, 11, 0, 0, 0, 0, 1, 0, 7 },
+//       { 0, 0, 2, 0, 0, 0, 6, 7, 0 }};
+      int G[V][V];
+      cout<<"Enter the graph"<<endl;
+      for(int i=0;i<V;i++)
+       {
+           for(int j=0;j<V;j++)
+           {
+            cin>>G[i][j];
+           }
+         cout<<"\n";
+       }
+
+
+      cout<< "\nSource vetiex is 0\n"<<endl;
+      cout<<"following shows SHORTEST Distance of vertices from source vertex \n\n"<<endl;
+      Dijkstra(G, 0);  
+      return 0;
+}