Question

Consider the following C program: \begin{verbatim} #include stdio.h int main(){ int a = 6; int b = 0; while(a<10) { a = a / 12 + 1; a += b; } printf("%d", a); return 0; } \end{verbatim} Which one of the following statements is CORRECT?

• A. The program prints 9 as output.
• B. The program prints 10 as output.
• C. The program gets stuck in an infinite loop.
• D. The program prints 6 as output.

Hint:

In C, integer division truncates the decimal part, which can lead to unintended infinite loops if the update condition depends on such operations.

Answer 1

The Correct Option is C

Step 1: Analyze the program.
Initially, $a = 6$ and $b = 0$.
Inside the \texttt{while} loop, the value of $a$ is updated as: $$a = \frac{a}{12} + 1.$$
In integer arithmetic, dividing $a$ (initially 6) by 12 results in 0 since only the integer part is retained. Hence: $$a = 0 + 1 = 1.$$
The next statement is: $$a += b.$$ Since $b = 0$, $a$ remains 1. Step 2: Infinite loop condition.
The condition for the \texttt{while} loop is $a<10$. After the first iteration: $$a = 1 \quad \text{(remains unchanged as \( b = 0 \))}.$$
In subsequent iterations, $a$ is repeatedly updated to 1 (because $a / 12 + 1 = 1$), and the loop never terminates. Final Answer: $$\boxed{\text{The program gets stuck in an infinite loop.}}$$