Summary of "Depth First Search (DFS) with example | Uninformed Search | Artificial Intelligence"
Summary of Video on Depth First Search (DFS)
Main Ideas and Concepts:
- Definition and Classification:
- Depth First Search (DFS) is an uninformed search technique in artificial intelligence, similar to Breadth First Search (BFS).
- Both algorithms operate without prior knowledge of the domain or goal state.
- Mechanism of DFS:
- DFS uses a stack data structure (Last In First Out - LIFO) to explore nodes.
- The algorithm goes deep into the graph or tree until it reaches a leaf node, then backtracks to explore other paths.
- Traversal Process:
- Starting from a node (e.g., A), the algorithm can choose to explore child nodes (e.g., B and C) in any order.
- The sequence of exploration can vary, but the underlying logic remains focused on reaching the deepest node first.
- Backtracking:
- Once a leaf node is reached, the algorithm backtracks to the parent node to explore other unexplored paths.
- Characteristics of DFS:
- Incomplete: DFS may not find a solution if the search space is infinite or if cycles exist, potentially leading to infinite loops.
- Non-Optimal: DFS does not guarantee an optimal solution; it may find a solution that is more costly than another possible solution.
- Time Complexity: The time complexity is generally O(V + E) (where V is the number of vertices and E is the number of edges) or O(b^d) in terms of branching factor (b) and depth (d).
- Comparison with BFS:
- Unlike DFS, BFS is complete and will always find the shortest path if one exists, as it explores all nodes at the present depth before moving deeper.
Methodology/Instructions:
DFS Traversal Steps:
- Start at the initial node and push it onto the stack.
- While the stack is not empty:
- If a node has no children, backtrack by popping the stack until a node with unvisited children is found.
Key Points:
- DFS operates on present knowledge without heuristic evaluations.
- It may lead to non-optimal solutions and can be incomplete in certain scenarios.
Speakers/Sources:
The video is presented by "Gate Smashers."
Category
Educational
