COS3751 Exam Pack 2026

COS3751

EXAM PACK

,COS3751- OCTOBER/NOVEMBER 2025

Complete Answers

QUESTION 1: Solving Problems by Searching [10 Marks]

The crossword contains:

 Horizontal: ICE, BET, NAP
 Vertical: PET, NIB, ACE

We need to arrange the three horizontal words so that the columns form the three
vertical words.

Search tree

A search can be constructed by trying each possible word in the first row and checking
whether the partial assignment can still produce valid vertical words.

The successful path is:

START
|
Choose Horizontal Word
for Row 1
/ | \
ICE BET NAP
|
Row 1 = NAP
|
Choose Row 2 = ICE
|
Choose Row 3 = BET
|

, Check columns
/ | \
NIB ACE PET
|
GOAL

The completed crossword is:

C1 C2 C3


Row 1 N A P
Row 2 I C E
Row 3 B E T

Therefore:

 Horizontal: NAP, ICE, BET
 Vertical:
o Column 1 = NIB
o Column 2 = ACE
o Column 3 = PET

Final answer

NAPICEBET\boxed{ \begin{array}{ccc} N&A&P\\ I&C&E\\ B&E&T \end{array}}

All six words fit correctly.




QUESTION 2: Adversarial Search and Games [27 Marks]

2.1 Minimax [7 Marks]

From the first game tree:

,  A = MAX
 B, C = MIN
 D, E, F, G = MAX

Leaf values:

D: 5, 8
E: 3, 1
F: 2, 4
G: 6, 7

a) D

D is a MAX node:

D=max⁡ (5,8)=8D=\max(5,8)=\boxed{8}

b) E

E=max⁡ (3,1)=3E=\max(3,1)=\boxed{3}

c) F

F=max⁡ (2,4)=4F=\max(2,4)=\boxed{4}

d) G

G=max⁡ (6,7)=7G=\max(6,7)=\boxed{7}

e) B

B is a MIN node:

B=min⁡ (D,E)B=\min(D,E) B=min⁡ (8,3)=3B=\min(8,3)=\boxed{3}

f) C