GATE 2020 Computer Science and IT Question Paper with answer


21. Question

S → aSB | d

 B  → b

“aaadbbb” which using a bottom-up parser, how many steps required?

 




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22. Question

Which of the following regular expression will contain a set of all binary strings containing an odd number of 1’s?




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23. Question

Given L = {an|n ≥ 0} ∪ {anbn| n ≥ 0}. Tell us where L is




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24. Question

Given four languages, which of the following are undecidable? Where <M> denotes encoding of a turing Machine M

L1 = {<M> | L(M) = ∅}

L2 = {<M> | L(M) is non recursive}

L3 = {< M, w, q > | M will visit the  state q when M execute on w and take exactly 100 steps]

L4  = {<M> | L (M) accept strings where strings length is atleast 20}

Which on of the following are/is undecidable?




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25. Question

A 16- bit instruction having two type of instruction i. e R – type and I- type where 16- bit instruction supports 64 registers set. Now I-type of instruction has 1 register field and 4-bit immediate field. R- type instruction supports 2 register address field and given that there are 8 different I-type instruction then how many different R-type of instruction are possible ___




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