From a894cc9563c43e7d5df21915aa8f5925311edc56 Mon Sep 17 00:00:00 2001
From: Aditya Maheshwari <73491810+AdityaDarak007@users.noreply.github.com>
Date: Thu, 13 Oct 2022 04:00:42 -0700
Subject: [PATCH] Create Dijkstra Algorithm

---
 Dijkstra Algorithm | 84 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 Dijkstra Algorithm

diff --git a/Dijkstra Algorithm b/Dijkstra Algorithm
new file mode 100644
index 0000000..b2ad0dd
--- /dev/null
+++ b/Dijkstra Algorithm	
@@ -0,0 +1,84 @@
+import java.util.*; 
+
+class Node implements Comparator<Node>
+{
+    private int v;
+    private int weight;
+
+    Node(int _v, int _w) { v = _v; weight = _w; }
+
+    Node() {}
+
+    int getV() { return v; }
+    int getWeight() { return weight; }
+
+    @Override
+    public int compare(Node node1, Node node2) 
+    { 
+        if (node1.weight < node2.weight) 
+            return -1; 
+        if (node1.weight > node2.weight) 
+            return 1; 
+        return 0; 
+    } 
+}
+
+class Main
+{
+    void shortestPath(int s, ArrayList<ArrayList<Node>> adj, int N)
+    {
+        int dist[] = new int[N];
+
+        for(int i = 0;i<N;i++) dist[i] = 100000000;
+        dist[s] = 0; 
+
+        PriorityQueue<Node> pq = new PriorityQueue<Node>(N, new Node());
+        pq.add(new Node(s, 0));
+
+        while(pq.size() > 0) {
+            Node node = pq.poll();
+
+            for(Node it: adj.get(node.getV())) {
+                if(dist[node.getV()] + it.getWeight() < dist[it.getV()]) {
+                    dist[it.getV()] = dist[node.getV()] + it.getWeight(); 
+                    pq.add(new Node(it.getV(), dist[it.getV()]));
+                }
+            }
+        }
+        System.out.println("The distances from source "+s+" are : ");
+        for (int i = 0; i < N; i++)
+        {
+            System.out.print( dist[i] + " ");
+        }
+    }
+    public static void main(String args[])
+    {
+        int n = 5;
+        ArrayList<ArrayList<Node> > adj = new ArrayList<ArrayList<Node> >();
+
+		for (int i = 0; i < n; i++) 
+			adj.add(new ArrayList<Node>());
+
+		adj.get(0).add(new Node(1, 2));
+		adj.get(1).add(new Node(0, 2));
+
+		adj.get(1).add(new Node(2, 4));
+		adj.get(2).add(new Node(1, 4));
+
+		adj.get(0).add(new Node(3, 1));
+		adj.get(3).add(new Node(0, 1));
+
+		adj.get(3).add(new Node(2, 3));
+		adj.get(2).add(new Node(3, 3));
+
+		adj.get(1).add(new Node(4, 5));
+		adj.get(4).add(new Node(1, 5));
+
+		adj.get(2).add(new Node(4, 1));
+		adj.get(4).add(new Node(2, 1));
+
+		Main obj = new Main(); 
+		obj.shortestPath(0, adj, n); 
+
+    }
+}