Dijkstra's algorithm is definitely complete and optimal that you will always find the shortest path. However it tends to take longer since it is used mainly to detect multiple goal nodes.
Therefore, dijkstra has the advantage over A* which is that it works for any general graph (with the exception of A* being faster in some cases). It could well be that certain implementations use these algorithms interchangeably, resulting in different results.
I'm learning the Dijkstra algorithm and I am testing out this code from GeeksforGeeks. I want the program to print the path for the shortest distance between 2 nodes as well. I defined: int parent[...
As per my understanding, I have calculated time complexity of Dijkstra Algorithm as big-O notation using adjacency list given below. It didn't come out as it was supposed to and that led me to unde...
It says A* is faster than using dijkstra and uses best-first-search to speed things up. A* is basically an informed variation of Dijkstra. A* is considered a "best first search" because it greedily chooses which vertex to explore next, according to the value of f(v) [f(v) = h(v) + g(v)] - where h is the heuristic and g is the cost so far. Note that if you use a non informative heuristic ...
I was reading about worst case time complexity for the Dijkstra algorithm using binary heap (the graph being represented as adjacency list). According to Wikipedia and various stackoverflow questions, this is O((V + E) logV) where E - number of edges, V - number of vertices.
Variants of Dijkstra's Algorithm The key is there are 3 kinds of implementation of Dijkstra's algorithm, but all the answers under this question ignore the differences among these variants. Using a nested for -loop to relax vertices. This is the easiest way to implement Dijkstra's algorithm. The time complexity is O (V^2).
Dijkstra's algorithm runs on positive weighed graphs, otherwise the priority queue would be useless. In your example, Dijkstra's algorithm would work because the graph is both weighed (positively) and has directed edges. The fault would have been that the edges have been double-assigned in the form of an undirected graph.
I understand what Dijkstra's algorithm is, but I don't understand why it works. When selecting the next vertex to examine, why does Dijkstra's algorithm select the one with the smallest weight? Wh...
