TRAKLA2 - Dijkstra‘s algorithm

Dijkstra‘s algorithm

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Task Instructions The task is to solve the single-source shortest-paths problem. The spanning tree is already initialized with the root vertex A, and thus does not containt the edge (A.father, A). Apply the algorithm to the following weighted graph (represented as an adjacency list beside the graphical representation) with the rest of the vertices. In case there exist several items with the same priority, the priority queue behaves like a queue (i.e., the oldest item is removed first). Some additional problems. In this exercise you can only click edges, i.e., apply the algorithm by adding edges to the spanning tree in correct order. The color of the spanning tree is red. Hint: You can adjust the layout of the graph by changing the font size.
SSSP-Dijkstra SSSP-Dijkstra(G,root) // G = (V,E,W) 1 for each u in V 2 do u.priority = MAX_VALUE; 3 u.unvisited = TRUE 4 u.father = NULL 5 root.priority = 0 // root in V 6 Q.Insert(root); // Priority Queue Q 7 while Q not empty 8 do u = DeleteMin(Q) 9 u.unvisited = FALSE 10 add edge (u.father, u) into the spanning tree 11 for each (u,v) in E 12 do if v.unvisited and u.priority + W(u,v) < v.priority 13 then v.father = u 14 v.priority = u.priority + W(u,v) 15 Q.InsertOrUpdate(v)