중간고사 기출

1. What is the output of the following C++ code?

#include <iostream>
void main()
{
		int y = 0;
		for (int i = 5; i > 0; i--) {
			if(i % 3 == 1)
					y++;
			else
					y += i;
				std::cout << "y = " << "\n";
		}
}	

2. The following code generates errors at compile time.

1. Find all incorrect statements.
2. correct the code and
3. show the output of the corrected code

#include <iostream>
void fun(int &r, int v) {
		r = r + 100;
		v = v - 100;
}
void main()
{
		int i = 2;
		int j = 3;
		int &rl = i;
		int &r2;
		r2 = j;
		fun(i, j);
		std::cout << "i : " << i << std::endl;
		std::cout << "j : " << j << std::endl;
}

1. The correct form of the incorrect statements (Write the corrected code)
   ▶

   답

   void fun(int &r, int v) {

   int &r2;

   r2 = j;

2. The incorrect statements in tha above code:
   ▶

   답

   int v → int &v

   int &r2 = j;
3. Output of the working code :
   ▶

   답

   i = 102 j = -97
4. Is is acceptable(i.e., without generating errors) to modify the definition of the variable ‘i’ to : const int i = 2; Explain your decision :
   ▶

   답

   Because “const” mean it cannot be changed, so trying to modify a const variable in “fun” will result in complie error.

3. Given the following function definition

int g(int x) {
		if (x <= 0)
				return x + 1;
		else 
				return g(x - 1) + g(x - 1) + g(x - 1);
}

1. Write an equivalent iterative function definition (loop-based function definition) for the above recursive function:
   ▶

   답

   복사

   c++

   int g(int x) {
   		if(x <= 0)
   				return x + 1;
   				
   		int result = 1;
   		for(int i = 1 ; i <= x ; i++) {
   				result = 3 * result;
   		}
   		return result;
   }

2. What is the returned value for g(3)?
   ▶

   답

   27
3. What will be the returned value for g(100) if the condition in the second line of the function is altered from x ≤ 0 to x < 0.
   ▶

   답

   0