ISRO CSE 2018 PYQ

Peephole optimization examines a small sliding window (peephole) of target instructions repeatedly to replace redundant or inefficient instructions.

Total instruction length = 3(m+10) + n bits, which is not equal to 3m+n bits. Hence 'none of the above'.

{AND, OR} cannot express negation (NOT gate), so it is not functionally complete.

Evaluating the Entries:
• I. pick: This is a 4-letter word. Since 4 is an even length, it cannot be derived by this grammar. (Invalid)
• II. picks: This is a 5-letter word. Since 5 is an odd length, it can be derived:
<word> \(\rightarrow \) <letter><charpair> \(\rightarrow \) p <charpair><letter><letter> \(\rightarrow \) p <letter><letter> k s \(\rightarrow \) p i c k s. (Valid)
• III. c44: This matches <letter><intpair>, where <intpair> generates two digits (44):
<word> \(\rightarrow \) <letter><intpair> \(\rightarrow \) c <integer><integer> \(\rightarrow \) c 4 4. (Valid)