Dfs Vs Bfs: What Is The Difference?

By Author: Billy Peterson
Total Articles: 5
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As a Computer Science student, I know how much it is important to understand the most popular and important tree traversal algorithms. So, I suggest every beginner should clarify the basic differences between these two algorithms.

Breadth-first - search(BFS) and depth-first-search(DFS) are the most popular tree traversal algorithms. Both techniques include visiting all the edges and vertices of a graph but the most important difference between them is, they perform different data structures. BFS applies Queue data structure and DFS applies the Stack data structure. Depending on this difference we can determine between the two methods which one is appropriate for a particular purpose.

In this article, I will discuss the key differences between DFS and BFS.

What Is Depth-First Search?
Depth-First-Search is a recursive algorithm that is used to find trees or graph a data structure. This algorithm uses the concept of backtracking and searches in-depth ward directions. The implementation of this algorithm starts at the root node and searches as far as possible before the backtracking process. DFS ...
... uses the stack data structure to recall when a dead-end comes, to pick the further nodes.

Learn more about the Depth First Search Java.

What Is Breadth-First-Search?
The breadth-First-Search algorithm is a non-recursive algorithm used to search or traverse trees or graph a data structure. The implementations of this algorithm begin by selecting a single node or tree root as the initial point and explore all the neighbor nodes. After the visit and marking the starting node the algorithm progresses towards the unvisited nearest nodes and analyzes them. The BFS algorithm uses the queue data structure to check whether a node has been found out before enqueueing the node. This algorithm explores the nearest node branch as far as possible before the backtracking process, it is exactly the opposite strategy of Depth-First-Search.

Learn more about the Breadth-First-Search algorithm.

DFS vs BFS - Key Differences:

Depth-First-Search(DFS)
Breadth-First-Search(BFS)
DFS begins the searching from the root node and explores the nodes as far as possible from the root node.

It uses the stack data structure to remember the next node visit.

DFS needs less memory than BFS to store.

It is applied using the LIFO list.

Not ideal for finding the shortest distance.

This algorithm is used for problem-solving, topological sorting which needs backtracking of the graph, identifying the cycles in a graph, and discovering the paths between two nodes, etc.
BFS starts the searching from the root node and explores all the neighbor roots according to the tree level mode.

It uses the queue data structure to remember the next node visit.

BFS needs more memory than DFS.

It is applied using the FIFO list.

Ideal for finding the shortest path.

This algorithm is used for finding the shortest path between two nodes, discovering all the connected components in the graph, analyzing if a graph is bipartite or not, etc.