Cognizant Coding and Programming Round 2

Question 1

What is the time complexity of binary search on a sorted array of n elements?

Accepted Answer

O(log n)

Answer

Binary search halves the search space each step, yielding O(log n) time complexity.

Question 2

Which data structure is used to implement a recursive function call stack?

Accepted Answer

Stack

Answer

Function calls are pushed onto a call stack and popped when functions return, following LIFO order.

Question 3

In Python, what does the 'self' parameter in a class method refer to?

Accepted Answer

The current instance of the class

Answer

'self' refers to the current object instance, allowing access to its attributes and methods.

Question 4

What will be the output of: print(type(1/2)) in Python 3?

Accepted Answer

Answer

In Python 3, the / operator always returns a float, so 1/2 yields 0.5 of type float.

Question 5

Which sorting algorithm has the best average-case time complexity?

Accepted Answer

Merge Sort

Answer

Merge Sort has O(n log n) average-case complexity, better than O(n²) algorithms like Bubble, Selection, or Insertion Sort.

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