Uninformed search algorithms, also known as blind search, explore the search space systematically without using any specific knowledge about the problem domain or the goal's location. They expand nodes based solely on the information available during the search process.
In contrast, informed search algorithms utilize a heuristic function, $h(n)$, which estimates the cost from the current node $n$ to the nearest goal. This heuristic guides the search more efficiently towards the goal.
A* Search is a prominent example of an informed search algorithm. It evaluates nodes using a function $f(n) = g(n) + h(n)$, where $g(n)$ is the known cost from the start node to node $n$, and $h(n)$ is the heuristic estimate of the cost from node $n$ to the goal. Because A* uses the heuristic function $h(n)$, it is considered an informed search strategy.
Since A* Search employs heuristic information to guide its search, it does not belong to the category of uninformed search algorithms. The other options (BFS, DFS, DLS) are standard uninformed search techniques.
Consider a state space where the start state is number 1. The successor function for the state numbered $n$ returns two states numbered $n+1$ and $n+2$. Assume that the states in the unexpanded state list are expanded in the ascending order of numbers and the previously expanded states are not added to the unexpanded state list.
Which ONE of the following statements about breadth-first search (BFS) and depth-first search (DFS) is true, when reaching the goal state number 6?