Problems tagged with "start and finish times"

Suppose a depth-first search (DFS) is run on the graph shown below using node \(s\) as the source and adopting the convention that a node's neighbors are produced in ascending order of their label.

Let \(G\) be a graph, and suppose \(s\), \(u\), and \(v\) are three nodes in the graph.

Suppose a depth-first search (DFS) is run on \(G\) using node \(s\) as the source and adopting the convention that a node's neighbors are produced in ascending order by label. During this DFS, start and finish times are computed. Suppose it is found that:

Now suppose another DFS is run using node \(s\) as the source, but adopting a different convention about the order in which neighbors are produced. Suppose new_start and new_finish are the start and finish times found by this second DFS. True or False: it must be that

Suppose again that a DFS is run on the graph shown in the above problem using node 11 as the source.

In a DFS on an undirected graph \(G\), the start time of node \(u\) is 12, while the finish time of node \(u\) is 37. How many nodes were marked pending between the moment that node \(u\) was marked pending and the moment that it was marked visited? Node \(u\) itself should be excluded from your count.

Suppose a depth first search is run on the graph shown below using node \(u_4\) as the source, and adopt the convention that graph.neighbors produces nodes in ascending order of label. Which node will have the smallest finish time?

Suppose a depth first search is run on the graph shown below using node \(u_4\) as the source, and adopt the convention that graph.neighbors produces nodes in ascending order of label. What will be the start time of node \(u_7\)?

Suppose \(T = (V, E)\) is a connected, undirected graph with no cycles (that is, \(T\) is a tree). Suppose a depth first search is run on \(T\) using node s as the source. Assume that node s has two neighbors: \(u\) and \(v\). If \(|V| = 15\), which one of the below represents possible start and finish times of \(u\) and \(v\)? You may assume that graph.neighbors produces neighbors in ascending order of label.