trí tuệ nhân tạo,cao hoàng trụ,dhbkhcm TRƯỜNG ĐẠI HỌC BÁCH KHOA TP HCM Khoa Khoa học & Kỹ thuật Máy tính ARTIFICIAL INTELLIGENCE Tut 2 Search Space and Strategies Question 1 Figure 1 – A road map of R[.]
Trang 1ARTIFICIAL INTELLIGENCE Tut 2 - Search Space and Strategies
Question 1
Figure 1 – A road map of Romania
Figure 1 gives a simplified road map of Romania Find a path from Bucharest to Timisoara using Depth-First-Search and Breadth-First-Search Assume that when performing the BFS traversal, the cities will be considered in counter-alphabetical order when in the same level
Question 2.
For each of the following problems, specify (i) a representation for a state; (ii) the start and goal states and (iii) the operators, each of which is followed by an example
Example problem: The water-jug problem in the lecture notes
State representation: a pair (x,y) where xand yare respectively the amounts of water in
4-litre and 3-litre jugs
Start state:(0,0)
Trang 2Operators:
- Fill up the first jug: (2,2) (4,2)
- Fill up the second jug: (2,2) (2,3) - Empty the first jug: (2,2)
(0,2)
- Empty the second jug: (2,2) (2,0)
- Fill up the first jug by the water in the second one: (2,3) (4,1) -
Fill up the second jug by the water in the first one: (2,1) (0,3)
- Empty the first jug to the second one: (1,1) (0,2) - Empty the
second jug to the first one: (2,1) (3,0)
a New Water Jug: This is a version of the famous water jug puzzle, which can be solved
systematically by casting it into the form of a search problem You are given a three pint jug named Three, and a four pint jug named Four You have no other measuring devices Either jug can be filled with water from a tap named Tap, and water can be discarded from either jug down a drain called Drain Water may also be poured from either jug into the other Initially both Three and Four are empty Your goal is to find a sequence of operations that will leave you with exactly two pints of water in Four
b The 8-queens problem: The eight-queens puzzle is the problem of putting eight chess queens
on an 8×8 chessboard such that none of them is able to capture any other using the standard chess queen's moves Figure 3 depicts one solution
Figure 3 – An example solution for the 8-queens problem
Trang 3c The goat and wolf problem: You are on the bank of a river with a boat, a cabbage, a goat, and
a wolf, and your task is to get everything to the other side Only you can handle the boat, and there is only space in the boat for you and one additional item You can’t leave the goat alone with the wolf or the cabbage, or something will get eaten Use a state space search formulation
to solve your problem
d Touring problem: Visit every city in Figure 4 at least once, starting, and ending in
Bucharest
Figure 4: A road map of Romania
Question 3
a Explain carefully the distinction between a state space graph and a search tree Discuss the potential trade-off between short solutions and good solutions, and between computational costs and other costs
b Analyze 8-queens problem in Question 2 with respect to the seven problem characteristics discussed in Chapter 2