In C++ (const parameters and integer arithmetic), determine the output of the following code. Consider integer operator precedence and the final multiplication by 0.2. #include<iostream.h> const double CuriousTabConstant(const int, const int = 0); int main() { const int c = 2; cout << CuriousTabConstant(c, 10) << " "; cout << CuriousTabConstant(c, 20) << endl; return 0; } const double CuriousTabConstant(const int x, const int y) { return ( (y + (y * x) * x % y) * 0.2 ); }

Difficulty: Easy

Correct Answer: The program will print the output 2 4.

Explanation:


Introduction / Context:
The challenge is to simplify a mixed expression with integer multiplication, modulus, and then a scaling by a floating constant. Because of integer properties, one term collapses to zero, leaving a simple proportional result based solely on y.


Given Data / Assumptions:

  • x = 2; calls use y = 10 and y = 20.
  • Expression: y + (y * x) * x % y all in integer arithmetic, then multiplied by 0.2.


Concept / Approach:
For any integers k and nonzero y, (k * y) % y = 0. Here (y * x) * x is clearly a multiple of y, so the modulus term vanishes. The remaining value is simply y, and the final multiplication by 0.2 yields y * 0.2.


Step-by-Step Solution:

Simplify: (y * x) * x % y = 0 So return = (y + 0) * 0.2 = y * 0.2 For y=10 → 10 * 0.2 = 2 For y=20 → 20 * 0.2 = 4


Verification / Alternative check:
Replacing 0.2 with 1.0/5.0 shows the same result; double formatting by default often prints without fixed decimals (e.g., "2 4").


Why Other Options Are Wrong:

  • 20 40 or 10 20: Ignore the final scale factor.
  • 20 4.50: Arithmetic is not producing 4.5 for the second value.
  • Compile-time error: Code is legal and compiles.


Common Pitfalls:
Misapplying operator precedence or assuming modulus binds differently; here parentheses make the intended grouping explicit.


Final Answer:
The program will print the output 2 4.

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