Question

Consider the following C code:

int main() {
    sum = 0;
    for (n = 1; n < 3; n++) {
        n++;
        sum += g(f(n));
    }
    printf("%d", sum);
}

int g(n) {
    return 10 + n;
}

int f(n) {
    return g(2 * n);
}
  

What is the output?

• A. 40
• B. 46
• C. 50
• D. 30

Hint:

In loops, always carefully track the variable increments and the order of function calls. Be sure to account for changes in the loop counter inside the loop body.

Answer 1

The Correct Option is B

Step 1: Analyze the for loop.

- The loop starts with \( n = 1 \). In each iteration of the loop:
- \( n++ \) increments \( n \) to 2 before the function calls.
- Then, \( f(n) \) is called with \( n = 2 \).


Step 2: Function call analysis.


1. For \( n = 1 \), after the increment, \( n = 2 \):
\[ f(2) = g(4) = 10 + 4 = 14 \] So, \( sum = 14 \).

2. For \( n = 2 \), after the increment, \( n = 3 \):
\[ f(3) = g(6) = 10 + 6 = 16 \] So, \( sum = 14 + 16 = 30 \).

After the loop ends, \( sum = 46 \).

Thus, the correct answer is \( 46 \).