[cse 471] Homework-2 Announcements (grade distribution, marking scheme and a missing solution..)

Hi,

 

Grade Distrubution for Homework-2 :

 

Grad	avg:87.4	96(H)	74(L)
UG	avg:84.8	96(H)	72(L)

 

And marking scheme is as follows::

 

Total : 100 points

 

PART A:

1. 5

2. 6 (2+2+2)

3.

   Part A: 4 (2+2)

   Part B: 4

   Part C: 8

4.

  Part A: 3

  Part B: 3

 

5. 4

 

PART B: (true or flase )

 

18  (3 X 6)

 

[CSP1]

 

i. 5

ii. 3

iii. 6

 

[CSP2]

 

1.1 6

1.2 4

1.3 4

 

Qn. II (Pattern DB Heuristics)

 

A.

     A.1    2

     A.2    2

     A.3    3

     A.4    5

B.

      5

 

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And, first part of the CSP solution is missing from the solutions page on the course web-site. I am writing it down below:

 

[CSP1]

1. 

    Let Jobs be J1, J2, J3 and J4 and days are d1,d2,d3.

 

    Domains:  J1 = {d1,d2,d3}, J2 = {d1,d2,d3}, J3 = {d1,d2,d3}

 

    Constraints as no-goods:

       (J1>=J2), (J2>=J3 & J2>=J4),  (J3=J2) (J3=J4), (|J4 - J1| < 1)

 

2. No its not binary. (There is a ternary constraint)

 

3.  

     Using forward checking and dynamic variable ordering:

 

     path1 at root: pickup J2=d1, using forward checking J1={ } => this a FAIL case

 

     path2 at root: pickup J2 = d2. [ D(J1) = {d1} D(J3)= {d1,d3} D(J4) = {d1,d2,d3} ]

                              --> Followed by J1=d1  [ D(J3) = {d1,d3} D(J4) = {d3} ]

                                       --> Followed by J4=d3  [ (D(J3) = {d1} ]

                                               --> Followed by J3=d1 --> all variables are exhausted with no contraints => SUCCESS

 

    So, the assignment is  { J1,J3 = d1 ;  J2 = d2; J4 = d3 }

 

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Let me know if you have any questions.

 

Thanks,

Aravind