Question

Given an undirected graph that is a tree, give a linear time algorithm to find the two leaves in the tree that have the minimum distance between them.

Answer 1

Sol. Breadth-first search  is an algorithm for traversing or searching tree or graph data structures. It starts at the tree root or some arbitrary node of a graph, sometimes referred to as a 'search key' and explores the neighbor nodes first, before moving to the next level neighbors.

The S set is used to track which vertices have been visited . At the beginning of the algorithm, the set is empty. At the end of the algorithm, it contains all vertices with a distance from root less than the goal.

The parent attribute of each vertex is useful for accessing the nodes in a shortest path, for example by backtracking from the destination node up to the starting node, once the BFS has been run, and the predecessors nodes have been set. The time complexity can be expressed as O(|V|+|E|) since every vertex and every edge will be explored in the worst case. |V|is the number of vertices and |E|is the number of edges in the graph.

BFS is an undirected graph that is a tree, give a linear time algorithm to find the two leaves in the tree that have the minimum distance between them.

오 3 by using p 8p S 6 3