COT5310hw2key

# COT5310hw2key - COT 5310 Homework 2 Key (a) Present a...

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Unformatted text preview: COT 5310 Homework 2 Key (a) Present a Register Machine that computes FIB. Assume R1 = x ; at termination set R2 = 1 if x is a member of the Fibonacci sequence and 0 if not. 1. INC 4 [2] // set up R3 = 0 = l and R4 = 1 = h as the first two Fibonacci numbers 2. DEC 1 [3, 14] // move input R1 and R3 (= l ) to R5 , finish if cant decrement 3. DEC 3 [4, 5] 4. INC 5 [2] 5. INC 1 [6] // R1 is now x l 1, make it equal x l , this implies R3 =0 now 6. DEC 4 [7, 9] // move R4 (= h ) into R3 and copy to R6 7. INC 3 [8] 8. INC 6 [6] 9. DEC 5 [10, 12] // now R5 = l , move to R4 and R1 , thus restoring R1 to x 10. INC 1 [11] 11. INC 4 [9] 12. DEC 6 [13, 2] // move copy of h in R6 to R4 which contains h right now 13. INC 4 [12] 14. DEC 3 [16, 15] // if R3 = 0 then x FIB 15. INC 2 [16] 16. DEC 3 [16, 17] // begin cleanup to make things look pretty 17. DEC 4 [17, 18] 18. DEC 5 [18, 19] (b) Present a Factor Replacement System that computes FIB. Assume starting number is 3 x 5; at termi- nation, result is 2 = 2 1 if x is a member of the Fibonacci sequence; 1 = 2 otherwise. Actually, it can be done without the 5, but that may make it easier....
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## COT5310hw2key - COT 5310 Homework 2 Key (a) Present a...

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