深さ優先探索 (DFS)は基本的な algorithm used in コンピュータ科学 for traversing or searching tree or graph データ構造. The algorithm starts at the root node (or an arbitrary node in the case of a graph) and explores as far as possible along each branch before backtracking. This approach results in a depthward exploration of the structure.
DFSは、スタックデータ構造を使用して実装でき、明示的にスタックを使うか、再帰を通じて暗黙的に行います。アルゴリズムの手順は次のとおりです。
- ルート（または任意のノード）から開始します。
- ノードを訪問済みとしてマークします。
- 未訪問の隣接ノードを探索し、構造の奥深くへ進みます。
- ノードに未訪問の隣接ノードがなければ、最後に訪問した未訪問の隣接ノードを持つノードにバックトラックします。
DFS is particularly useful for problems where a solution might be found deep within the structure, such as solving mazes, puzzle-solving, or conducting searches in 人工知能 applications. It can also be leveraged to find connected components in graphs or to perform topological sorting.
However, DFS has its limitations, such as the potential for deep recursion leading to stack overflow and the inability to find the shortest path in unweighted graphs. Due to its nature, it may explore paths that do not lead to a solution, making it less efficient in some scenarios compared to other algorithms 幅優先探索（BFS）のようなものです。