Create Prim's_Algorithm.java

Algoritms/Prim's_Algorithm.java

@@ -0,0 +1,72 @@
+import java.io.*;
+import java.util.*;
+
+// Class to form pair
+class Pair implements Comparable<Pair>
+{
+    int v;
+    int wt;
+    Pair(int v,int wt)
+    {
+        this.v=v;
+        this.wt=wt;
+    }
+    public int compareTo(Pair that)
+    {
+        return this.wt-that.wt;
+    }
+}
+
+class GFG {
+
+// Function of spanning tree
+static int spanningTree(int V, int E, int edges[][])
+    {
+         ArrayList<ArrayList<Pair>> adj=new ArrayList<>();
+         for(int i=0;i<V;i++)
+         {
+             adj.add(new ArrayList<Pair>());
+         }
+         for(int i=0;i<edges.length;i++)
+         {
+             int u=edges[i][0];
+             int v=edges[i][1];
+             int wt=edges[i][2];
+             adj.get(u).add(new Pair(v,wt));
+             adj.get(v).add(new Pair(u,wt));
+         }
+         PriorityQueue<Pair> pq = new PriorityQueue<Pair>();
+         pq.add(new Pair(0,0));
+         int[] vis=new int[V];
+         int s=0;
+         while(!pq.isEmpty())
+         {
+             Pair node=pq.poll();
+             int v=node.v;
+             int wt=node.wt;
+             if(vis[v]==1) 
+             continue;
+
+             s+=wt;
+             vis[v]=1;
+             for(Pair it:adj.get(v))
+             {
+                 if(vis[it.v]==0)
+                 {
+                     pq.add(new Pair(it.v,it.wt));
+                 }
+             }
+         }
+         return s;
+    }
+
+    // Driver code
+    public static void main (String[] args) {
+        int graph[][] = new int[][] {{0,1,5},
+                                    {1,2,3},
+                                    {0,2,1}};
+
+        // Function call
+        System.out.println(spanningTree(3,3,graph));
+    }
+}