Lecture 4 Flashcards
Which is a graph and which is a tree for state space and search space?
State space is a graph, and search space is a tree.
What are the frontier nodes?
A set of nodes that have been reached but not expanded.
What is the fundamental difference in search algorithms? (code wise)
How they pick the next node to expand from the frontier
What is a Uniformed Search?
A search that has no additional information about states beyond what has been provided in the problem formulation.
How does DFS work?
Expand the deepest node first using a LIFO stack.
Is DFS complete?
No, if the graph is infinitely large, it could forever expand in one direction away from the goal.
Is DFS optimal?
No, it finds the leftmost solution regardless of cost and depth.
How does BFS work?
Explores the shallowest node first using a FIFO queue.
Is BFS complete?
Yes, the depth must be finite if a solution exists.
When is BFS optimal?
when all costs are 1
When will BFS outperform DFS? What about other way?
BFS better for finding close goals, DFS better for “left” goals.
What is iterative Deepening Search?
Runs repeated Depth limited searches on each layer. (research more, dont understand it vs BFS)
Does BFS find the shortest path?
No, it finds the least number of actions! Not the lease cost path!
How does uniform cost search work?
It processes the cheapest node at a time.
Is uniform cost search complete and optimal?
Yes!
