Unit -2 Control Statements and Sorting Algorithms

Which of the following is NOT a control statement in C/C++?

• if-else

• switch

• for

• class

What is the main purpose of a loop invariant?

• To ensure faster execution

• To prove correctness of a loop

• To reduce memory usage

• To determine loop termination condition

A loop invariant must hold:

• Only before the loop starts

• Before and after every iteration

• Only after the loop ends

• Randomly during execution

Loop invariants are mainly used in:

• Compiler optimization

• Algorithm correctness proofs

• Data compression

• File handling

If a while loop runs n times, proving correctness requires:

• Base case, inductive step

• Just loop termination

• Big-O analysis

• Deadlock freedom

The "termination condition" in a loop guarantees:

• No segmentation fault

• Loop eventually ends

• Algorithm is stable

• Minimum space complexity

Which of the following is a variant function used in correctness proofs?

• A function that strictly decreases with each iteration

• A function that increases arbitrarily

• A constant function

• A random number generator

The correctness of sorting algorithms is usually proven using:

• Divide and conquer

• Loop invariants

• Heap property

• Hashing

Which control statement can cause infinite loops if used incorrectly?

• break

• continue

• while

• switch

Partial correctness means:

• Algorithm always halts with correct output

• If algorithm halts, output is correct

• Algorithm never halts

• Algorithm is both fast and correct