TIFR CSE 2017 | Part B | Question: 5

Question

Consider the following psuedocode fragment, where $y$ is an integer that has been initialized.

int i=1
int j=1
while (i<10):
    j=j*i
    i=i+1
    if (i==y):
        break
    end if
end while

Consider the following statements:

1. $(i==10)$ or $(i==y)$
2. If $y > 10$, then $i==10$
3. If $j=6$, then $y==4$

Which of the above statements is/are TRUE at the end of the while loop? Choose from the following options.

• A. i only
• B. iii only
• C. ii and iii only
• D. i, ii, and iii
• E. None of the above

Answer 1

Consider the situations when loop gets broken -

1. If $i$ becomes $10$, or $i$ becomes equal to $y$. $\Longrightarrow$ (i) is correct.
2. If $y > 10$, the control will come out of the loop when $i$ becomes $10$. $\Longrightarrow$ (ii) is correct.
3. During $1$^st iteration, $j =1, i =2$
   • $2$^nd iteration, $j = 2, i =3$
   • $3$^rd iteration, $j = 6, i =4$

$4^{th}$ iteration must not occur because $j$ will become $24$. Hence during $3^{rd}$ iteration break statement must have been executed and hence, $y$ must be equal to $4$ (equal to $i$ during the $3^{rd}$ iteration).

This implies (iii) is also correct.

Hence, Option D is correct.

Comments

Yes, I agree. Ans should be option D.

@Arjun sir , Is there any nitpick here ??

---

nopes. We have to see all options.

---

Thanks sir. :)

I was worried about some negative Y and about 3rd options: But each option satisfies for some cases. :)

And no problem with -ve Y as well because in that case, the 1st case would satisfy.

Answer 2

All the three (i), (ii), (iii) are correct. Hence, (D).

Answer 3

we can solve by taking conditions one by one as an values/conditions.

Answer 4

while loop will end in cases:
1) if it satisfy if condition OR 
2) i=10

i.  CORRECT as it satisfy above 2 cases 
ii.  CORRECT as If y>10 means it not satisfy if condition so to end the whle loop it should be i==10
iii.  CORRECT check  tarun_svbk 's explanation 

Hence Ans is D