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标题: SDCAR2010【游戏入门】64-3 解析 [打印本页]

作者: sdcar2010    时间: 2011-12-12 23:26
标题: SDCAR2010【游戏入门】64-3 解析
在为期两天的新车测试赛中,车手:Ron, Steve, Tom, 和 Yong 每人在第一天要试开四辆新车:F, G, H, 和 J 之一。第二天,每位车手都要试开另一辆新车。而且每位车手每天只试开一辆新车;每天所有四辆新车都被试开。车手分配按如下规定:
Ron 不能开 F
Yong 不能开 J
Tom 必须是试开 H 的车手之一
头天 Yong 试开的车必须是 Steve 第二天试开的车


Analysis:
This is a tricky 2-dimentional game, in which you need to match cars with drivers. There are many different ways for you to diagram this problem. In fact, one key aspect of mastering the games is to develop your own preferred system for diagramming the problems. I chose the following one because I want to use the YS block as the key inference. As shown below, there are two frames. Frame 1 is not well-defined, but Frame 2 is pretty much set.

Another key aspect of mastering the games is to have a good memory of all the rules involved for each game. In this particular game, you have to keep in mind if a driver has been assigned to one car on one day, it cannot be assigned to another in the same day or the same car on the other day. That is the reason why in Frame 2 Y is assigned to F on the second day because T and R have to be assigned to H, and Y cannot be assigned to J.

SDCAR2010【游戏入门】64-2 解析

作者: sdcar2010    时间: 2011-12-12 23:46
13. Which one of the following is a possible assignment of drivers to cars, with the riders for each car listed in the order in which they test drive the car?
A) F: S, R;
   G: Y, S;
   H: T, Y;
   J: R, T
B) F: S, Y;
   G: R, T;
   H: Y, S;
   J: T, R
C) F: Y, S;
   G: S, R;
   H: T, Y;
   J: R, T
D) F: Y, S;
   G: T, R;
   H: R, T;
   J: S, Y
E) F: Y, T;
   G: S, Y;
   H: T, R;
   J: R, S

14) If Tom tests G on the second day, then which one of the following must be true?
A) Ron tests H on the 1st day
B) Ron tests J on the 1st day
C) Tom tests H on the 2nd day
D) Tom tests J on the 1st day
E) Yong test H on the 2nd day

15) Any of the following could be true EXCEPT:
A) Ron tests J on the 1st day
B) Ron tests J on the 2nd day
C) Steve tests H on the 1st day
D) Yong tests H on the first day
E) Yong tests H on the second day

16) Which one of the following CANNOT be true?
A) Ron tests G on the 2nd day
B) Steve tests F on the 1st day
C) Tom tests F on the 2nd day
D) Ron tests H on the 1st day
E) Yong tests F on the 2nd day

17) If Tom tests J on the first day, then which one of the following could be true?
A) Ron tests G on the 2nd day
B) Steve tests H on the 1st day
C) Yong tests H on the 2nd day
D) Steve is one of the testes for J
E) Tom is one of the testers for G

18) Which one of the following CANNOT be true?
A) Both Ron and Steve test J
B) Both Ron and Tom test J
C) Both Ron and Yong test G
D) Both Steve and Tom test G
E) Both Tom and Yong test F
作者: HarrisZheng    时间: 2011-12-13 17:18
13
R Y can not match F J respectively
A D out

H sould match T once
B out

Y sould follow By S
E out

thus C
作者: HarrisZheng    时间: 2011-12-13 17:35
14
If T test G on day2, then according to the constraint that T should match H once,  T test H on day1

and according to the constraint that Y must follow by S, Y can not match J , only car F is left for Y on day1,
so the diagram should be :

           day1      day2
F          Y            S
G                       T
H         T            Y
J

choice E matches the diagram
作者: HarrisZheng    时间: 2011-12-13 17:39
15
YS boundle and T matches H once bring that Y cannot match H on day1
so D
作者: HarrisZheng    时间: 2011-12-13 17:50
16
test such the most restrictive constraints like T and Y first
C if T matches F on day2 ,then he must match H on day1, leaving the only car on day1 for Y is car G
diagram

             day1           day2
F              S                  T  
G             Y                  S
H             T
J              R

then on day2 , either Y matches J or R matches J would be a violation  to the constraints.

So C
作者: HarrisZheng    时间: 2011-12-13 17:57
17

diagram
                    day1          day2
F
G
H                                      T
J                  T

CDE out
if R matches G on day2 , then YS bundle matches F , leaving the only car for Y on day2 is J, so A out

thus B
作者: HarrisZheng    时间: 2011-12-13 18:14
18
If Y matches the same car with anyone other than S, Y must on day2    , If S matches the same car with anyone other than Y, S must on day1

test the choices with S Y T first

D Both Steve and Tom test G

diagram
                 day1          day2
F                  Y                 S
G                 S                 T
H                 T
J                  R

then on day2 , either Y matches J or R matches J would be a violation  to the constraints.

D is the correct answer




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