SYNTEL Placement Paper -: Data Structure Questions With Answers

SYNTEL Previous Years Solved Sample Placement Papers

1. As compared to associative arrays, vector arrays are much
   

   a) Faster

   b) Slower

   c) Stable

   d) None of them

   Answer: a) Faster
2. Which function returns an array consisting of associative key/value pairs?
   

   a) count()

   b) array_count()

   c) array_count_values()

   d) count_values()

   Answer: c) array_count_values()
3. The updated MySQL extension released with PHP 5 is typically referred to as..
   

   a) MySQL

   b) mysql

   c) mysqli

   d) mysqly

   Answer: c) mysqli
4. What would be the Prefix notation for the given equation? A+(B*C)
   

   a) +A*CB

   b) *B+AC

   c) +A*BC

   d) *A+CB

   Answer: c

   Explanation: Reverse the equation or scan the equation from right to left. Apply the infix-postfix algorithm. The equation inside the bracket evaluates to CB* and outside the bracket evaluates to A+ therefore getting CB*A+. Reversing this and we get +A*BC.

5. What would be the Prefix notation for the given equation? (A*B)+(C*D)
   

   a) +*AB*CD

   b) *+AB*CD

   c) **AB+CD

   d) +*BA*CD

   Answer: a

   Explanation: Reverse the equation or scan the equation from right to left. Apply the infix-postfix algorithm. The equation inside the brackets evaluate to DC* and BA* respectively giving us DC*BA*+ in the end. Reversing this we get the +*AB*CD.

6. What would be the Prefix notation for the given equation? A+B*C^D
   

   a) +A*B^CD

   b) +A^B*CD

   c) *A+B^CD

   d) ^A*B+CD

   Answer: a

   Explanation: Reverse the equation or scan the equation from right to left. Apply the infix-prefix algorithm. The preference order in ascending order are as follows +*^. Operators are pushed into the stack and popped if its preference is greater than the one which is getting pushed. In the end all operators are popped. The equation evaluates to DC^B*A+. Reversing this we get our following answer.

7. Out of the following operators (^, *, +, &, $), the one having highest priority is _________
   

   a) +

   b) $

   c) ^

   d) &

   Answer: c

   Explanation: According to the algorithm (infix-prefix), it follows that the exponentiation will have the highest priority.

8. Out of the following operators (|, *, +, &, $), the one having lowest priority is ________
   

   a) +

   b) $

   c) |

   d) &

   Answer: c

   Explanation: According to the algorithm (infix-prefix), it follows that the logical OR will have the lowest priority.

9. What would be the Prefix notation for the given equation? A^B^C^D
   

   a) ^^^ABCD

   b) ^A^B^CD

   c) ABCD^^^

   d) AB^C^D

   Answer: a

   Explanation: Reverse the equation or scan the equation from right to left. Apply the infix-prefix algorithm. Here we have to remember that the exponentiation has order of associativity from right to left. Therefore the stack goes on pushing ^. Therefore resulting in ^^^ABCD.

10. What would be the Prefix notation for the given equation? a+b-c/d&e|f
    

    a) |&-+ab/cdef

    b) &|-+ab/cdef

    c) |&-ab+/cdef

    d) |&-+/abcdef

    Answer: a

    Explanation: Reverse the equation or scan the equation from right to left. Apply the infix-prefix algorithm. The preference order in ascending order are as follows |&+*/.

11. What would be the Prefix notation for the given equation? (a+(b/c)*(d^e)-f)
    

    a) -+a*/^bcdef

    b) -+a*/bc^def

    c) -+a*b/c^def

    d) -a+*/bc^def

    Answer: b

    Explanation: Reverse the equation or scan the equation from right to left. Apply the infix-prefix algorithm. The preference order in ascending order are as follows +*/^. Brackets have the highest priority. The equations inside the brackets are solved first.