Western Governors University (WGU) ICSC2100 C949 Data Structures and Algorithms I Practice Exam

A depth-first search (DFS) algorithm is characterized by its method of exploring as far down a branch of a tree or graph as possible before backtracking. This means that it will go deep into one path until it reaches a leaf node or dead end, and then, it will backtrack to explore other paths if necessary. This is achieved by utilizing a stack (either implicitly through recursion or explicitly through a data structure) to keep track of the nodes it has visited.

The essence of DFS is its focus on depth – it prioritizes exploring one branch of the graph or tree exhaustively before moving on to the next branch. This approach is particularly useful for applications such as topological sorting, solving puzzles with a unique solution, and scenarios where the depth of a solution is more favorable than breadth.

In contrast, the other options refer to different characteristics:

- Examining all nodes at a present depth first describes the breadth-first search (BFS) approach, where the algorithm explores all nodes at the current level before moving deeper.

- DFS does not require sorting of nodes; it simply proceeds from one node to unvisited neighbors.

- While DFS typically uses a stack rather than a queue, a queue is characteristic of breadth-first search algorithms.

Thus