Explanation: Breadth-first search is optimal when all step costs are equal, because it always expands the shallowest unexpanded node. If the solution exists in shallowest node no irrelevant nodes are expanded. 8. uniform-cost search expands the node n with the__________.
A. Lowest path cost
B. Heuristic cost
C. Highest path cost
D. Average path cost
Answer:A
Explanation: Breadth-first search is optimal when all step costs are equal, because it always expands the shallowest unexpanded node. If the solution exists in shallowest node no irrelevant nodes are expanded. 8. uniform-cost search expands the node n with the__________.
A. Lowest path cost B. Heuristic cost C. Highest path cost D. Average path cost
Explanation: uniform-cost search expands the node n with the lowest path cost. Note that if all step costs are equal, this is identical to breadth-first search. 9. Depth-first search always expands the ______ node in the current fringe of the search tree.