depth-first search

Also known as DFS, depth-first traversal, depth first search

algorithm for traversing or searching tree or graph data structures

Key facts

Class: Search algorithm
Data structure: Graph
Worst case performance: O ( | V | + | E | ) {\displaystyle O(|V|+|E|)} for explicit graphs traversed without repetition, O ( b d ) {\displaystyle O(b^{d})} for implicit graphs with branching factor b searched to depth d
Worst case space complexity: O ( | V | ) {\displaystyle O(|V|)} if entire graph is traversed without repetition, O(longest path length searched) = O ( b d ) {\displaystyle O(bd)} for implicit graphs without elimination of duplicate nodes
Optimal: no (does not generally find shortest paths)

via Wikipedia infobox

Described at

Depth first search - Wikimedia Commons

commons.wikimedia.org →

Link to a page describing this subject · 937 chars · not written by Vinony

~12 min read

Encyclopedic overview

Depth-first search (DFS) is an algorithm for traversing or searching tree or graph data structures. The algorithm starts at the root node (selecting some arbitrary node as the root node in the case of a graph) and explores as far as possible along each branch before backtracking. Extra memory, usually a stack, is needed to keep track of the nodes discovered so far along a specified branch which helps in backtracking of the graph.

A version of depth-first search was investigated in the 19th century by French mathematician Charles Pierre Trémaux as a strategy for solving mazes.

Excerpted from Wikipedia’s “depth-first search” article, available under the CC BY-SA 4.0 licence.