Dijkstra Algorithm Questions Medium
The visited set in the Dijkstra Algorithm is used to keep track of the vertices that have been explored or visited during the algorithm's execution. It helps in ensuring that each vertex is processed only once and prevents revisiting already explored vertices.
The main role of the visited set is to keep track of the shortest path distances from the source vertex to all other vertices in the graph. Initially, all vertices are marked as unvisited, and their shortest path distances are set to infinity. As the algorithm progresses, it selects the vertex with the minimum shortest path distance from the visited set and explores its neighboring vertices.
When a vertex is selected from the visited set, its shortest path distance is considered final, and it is marked as visited. The algorithm then updates the shortest path distances of its neighboring vertices if a shorter path is found. This process continues until all vertices have been visited or until the destination vertex is reached.
By using the visited set, the Dijkstra Algorithm ensures that it explores all possible paths from the source vertex to all other vertices in a systematic manner, guaranteeing that the shortest path distances are correctly calculated. It helps in avoiding unnecessary computations and improves the efficiency of the algorithm.