Question

Consider the following C program. Assume parameters to a function are evaluated from right to left.} \begin{verbatim} #include stdio.h int g(int p) { printf("%d", p); return p; } int h(int q) { printf("%d", q); return q; } void f(int x, int y) { g(x); h(y); } int main() { f(g(10), h(20)); } \end{verbatim} Which one of the following options is the CORRECT output of the above C program?

• A. 20101020
• B. 10202010
• C. 20102010
• D. 10201020

Hint:

When function parameters are evaluated right to left}, start with the last parameter, and carefully track the order of execution and the sequence of prints.

Answer 1

The Correct Option is A

The execution of the given C program proceeds as follows:
In the \texttt{main()} function, the function \texttt{f(g(10), h(20))} is called.
Parameters to the function \texttt{f()} are evaluated from right to left.
\texttt{h(20)} is evaluated first, printing \(20\) and returning \(20\).
\texttt{g(10)} is evaluated next, printing \(10\) and returning \(10\).
Therefore, the first part of the output is \(20\) followed by \(10\).
The function \texttt{f()} is then executed:
\texttt{g(x)} is called with \(x = 10\), printing \(10\).
\texttt{h(y)} is called with \(y = 20\), printing \(20\).
The second part of the output is \(10\) followed by \(20\).
Combining these parts, the total output is: \[ 20101020 \] Final Answer: \[ \boxed{20101020} \]