ONE 6th FORM Dijkstra v A* Search

What is the main difference between Dijkstra's algorithm and A* search?

• Dijkstra's algorithm is faster than A* search.
• A* search only works on unweighted graphs.
• Dijkstra's algorithm is uninformed and explores all paths, while A* uses heuristics to optimize the search towards the goal.
• Dijkstra's algorithm uses heuristics to find the shortest path.

What is a heuristic in the context of A* search?

• A heuristic is the exact cost to reach the goal from a node.
• A heuristic is a random guess about the goal.
• A heuristic is an estimate of the cost to reach the goal from a node.
• A heuristic is a method to find all possible paths in the search.

When does A* search behave exactly like Dijkstra's algorithm?

• When the heuristic function h(n) is zero for all nodes.
• When the algorithm is modified to use a random heuristic function.
• When the search space is fully connected with equal edge weights.
• When the heuristic function h(n) is equal to the actual cost for all nodes.

In Dijkstra's algorithm, which data structure is commonly used to select the next node to visit?

• Stack
• Linked list
• Array
• Priority queue

Which of the following is true about A* search?

• A* search is only optimal if the heuristic is consistent.
• A* search can be incomplete if the search space is infinite.
• A* search is optimal and complete when the heuristic is admissible.
• A* search is faster than Dijkstra's algorithm in all cases.

What does A* aim to minimize at each step of the algorithm?

• The distance from the start node to the current node.
• The heuristic estimate from the current node to the goal node.
• The total number of nodes expanded so far.
• The total estimated cost from the start node to the goal node.

Which case would make A* search and Dijkstra's algorithm equally efficient?

• Edge weights vary randomly.
• Only some edge weights are equal.
• All edge weights are equal.
• All edge weights are negative.

In a weighted graph what is an edge?

• A node or dot.

• A connecting line.

Can I run Dijkstra on a non-weighted graph?

• Yes

• No

Before looping through the nodes, what do we set as the values for the weights for all the nodes?

• The weights on the edges

• Set them all to infinity.

• Set them all to infinity and the starting one to zero.

• Set them all to infinity and leave the starting nodes' weight.