miku

2026-05-19 07:04:53 +05:30
parent 825e915f5f
commit 5beeb7c652
5 changed files with 254 additions and 0 deletions
@@ -0,0 +1,74 @@
+import java.util.*;
+public class dijkstra{
+    static int V;
+    static int minDistance(int[] dist, boolean[] visited){
+        int min = Integer.MAX_VALUE;
+        int minIndex = -1;
+        for(int v=0;v<V;v++){
+            if(!visited[v] && dist[v]<min){
+                min = dist[v];
+                minIndex = v;;
+            }
+        }
+        return minIndex;
+    }
+
+    static void printPath(int vertex, int[] parent){
+        if(vertex==-1) return;
+        printPath(parent[vertex], parent);
+        System.out.print(vertex+" ");
+    }
+
+    static void dijkstra(int[][] graph, int source){
+        int[] dist = new int[V];
+        boolean[] visited = new boolean[V];
+        int[] parent = new int[V];
+
+        Arrays.fill(dist, Integer.MAX_VALUE);
+        for(int i=0;i<V;i++)
+            parent[i] = -1;
+        dist[source] = 0;
+        long start = System.nanoTime();
+        for(int count=0;count<V-1;count++){
+            int u = minDistance(dist, visited);
+            visited[u] = true;
+            for(int v=0;v<V;v++){
+                if(!visited[v] && graph[u][v]!=0 && dist[u]!=Integer.MAX_VALUE && dist[u]+graph[u][v]<dist[v]){
+                    dist[v] = dist[u]+graph[u][v];
+                    parent[v] = u;
+                }
+            }
+        }
+        long end = System.nanoTime();
+
+        System.out.println("\nSHortest distances from source "+source+":");
+        for(int i =0;i<V;i++){
+            System.out.println("Vetex: "+i);
+            System.out.println("Cost: "+dist[i]);
+            System.out.println("Path: ");
+            printPath(i, parent);
+            System.out.println("\n");
+        }
+          long executionTime = end - start;
+
+        System.out.println("Execution Time: " + executionTime + " nanoseconds");
+    }
+
+        public static void main(String[] args){
+            Scanner sc = new Scanner(System.in);
+            System.out.println("\nENter number of vertices: ");
+            V = sc.nextInt();
+            int[][] graph = new int[V][V];
+            System.out.println("ENter adjacency matrix: ");
+            for(int i=0;i<V;i++){
+                for(int j =0;j<V;j++){
+                    graph[i][j] =sc.nextInt();
+                }
+            }
+            int source = 0;
+            dijkstra(graph, source);
+            sc.close();
+
+        }
+    }
+