The first assignment of artificial intelligence at Beijing University of Technology

Question 1: Use the status space to indicateA *SearchAlgorithmSolve the following problems:U2Choir in17They have to arrive at the concert venue within minutes, and they have to cross a bridge on the way. Four people start from the same end of the bridge. You have to help them reach the other end. The sky is dark, they only have one flashlight. At the same time, a maximum of two people can bridge the bridge together, while a flashlight must be held when crossing the bridge, so someone has to bring the flashlight back and forth to both ends of the bridge. A flashlight cannot be lost. The walking speed varies between the four people. If the two people walk with each other, the speed of the slow person prevails.
BonoFlowers required1Bridge in minutesEdgeFlowers required2Bridge in minutesAdamFlowers required5Bridge in minutes
LarryFlowers required10How are they going to bridge in minutes?17How about crossing the bridge within minutes? (Microsoft exam)

 

Answer:

Valuation Functions

F (n) = g (n) + H (N)

G (N)Defined as the past time

H (N)It indicates the estimated remaining time. When three of them are not crossing the bridge,H (N)The sum of the maximum bridge time and the minimum bridge time required. When two people do not cross the bridge,H (N)The maximum bridge time required. When a person does not cross the bridge,H (N)That is, the bridge time required. Because it does not consider the return time required to pass the flashlightH (N)It will not be longer than the actual time, and is estimated to be valid.

 

 

 

Correction: The status space is correct. The heuristic function is designed correctly.

 

 

Question 2:There is a game tree. The number in the last row is the static valuation of the page vertex. Please do the following for the game tree:

(1)
Calculate the reverse pushing value of each node by using the maximum minimization method.

(2)
Use pruning technology to cut unnecessary branches. (Use marker at the pruning position ).

 

 

Correct: The Reverse value is calculated correctly. The pruning process is correct.

 

 

 

 

Question 3:Search for information and describe the method of vertex valuation for a problem solved by using the game tree method. (For example, the method of vertex valuation in Chinese chess games)

 

Answer: for example, in the go sub-question, the goal of sub-computing is to obtain whether a piece of chess can be killed, whether it can be escaped, and how to eat or escape. You can use the game tree method to solve this problem.Proof-NumberSearch.

For node valuation, the evaluation of the key chain of the game block is used as the evaluation of the intermediate node and the leaf node.:

Node evaluation = # crucial chain's first liberties 3 4 + # crucial chain's second liberties

P n
Search divides nodes2Type:With nodes and or nodes.
Verify nodes at each node,Try to prove the node at each node or node.
Use on each node2Numeric Value: Proof number --Minimum number of leaf nodes to be expanded; Disproof number --The minimum number of leaf nodes to be expanded indicates whether the number of nodes is verified.