In all the algorithms, always explain their correctness and analyze their complexity. The complexity should be as small as possible.

Question 1: A directed tree is a rooted tree with all direction from parent to child. Let G(V, E) be a directed graph with positive weights l(e) on every edge e. A shortest path tree rooted at a vertex s is a directed tree containing all vertices, so that the distance Between s and any other vertex in V in the directed tree is the same as the distance in G. Show how to find a shortest path tree rooted at s in a directed graph. The weights are integer and positive