// Lab Test #1 Version #1
#include "stdstuff.h"

// Write the two functions indicated.  It is not necessary to write any 
// function prototypes.  Just write the complete functions at the top 
// of the file as indicated.

// Your functions must work for *any* input, not just for the examples 
// given in this main program.  You are welcome to add additional test
// cases.

// Note that program comments are required for full marks.


// This function (numberFacts) has three parameters and returns nothing (void).
// The first parameter is an integer.  
// The second parameter is "return"ed by the function.  
//     It is set to true if the first parameter is less than 0, and false otherwise.
// The third parameter is "return"ed by the function.
//     It is set to true if the first parameter is an exact multiple of 4 
//     (e.g. -4, 0, 4, 8, ...), and false otherwise.

void numberFacts( int x, bool &lessThanZero, bool &multFour ) {
   
   lessThanZero = (x<0); // true if x<0 and false otherwise
   multFour = (x%4==0); // true if x%4 is 0 and false otherwise
   
   // alternatively:
   // if (x<0)
   //    lessThanZero = true;
   // else
   //    lessThanZero = false;
   // if (x%4==0) // or x/4==x/4.0
   //    multFour = true;
   // else
   //    multFour = false;
   
}

// This function (arrayInfo) has three parameters and returns an integer.
// The first parameter is an integer indicating the length of the array.
// The second parameter an integer.
// The third parameter is an array of integers.
// If the first parameter (length of the array) is invalid (i.e. doesn't
// make sense), the function returns -1.
// Otherwise, this function returns the number of elements of the array 
// that are within 10 of the the second parameter (i.e. the difference
// between the array element and the second parameter is less than or
// equal to 10).
 
int arrayInfo(int n, int value, const int a[]){ // const optional
	
   int count = 0; // used to count the elements of the array within 10 of value
   
   if (n<1) // if array length is less than 1, we have a problem
      return -1; // indicate that the array length is invalid
   
   for (int i=0;i<n;i++) { // loop through the array
      if (abs(a[i]-value)<=10) // if | a[i] - value | <= 10
         count++;      // count it!
   }
   
   return count; // number of elements <= value
   	
}


int main()   // some tests of the functions above
{
   bool bool1, bool2;
   int answer;
   int array[6] = { 15, 0, -5, 10, 45, 789};
   
   // Testing numberFacts
   
   // set the bools incorrectly to make sure the function is working properly
   bool1 = true; bool2 = false;
   
   numberFacts(8, bool1, bool2); // first test of numberFacts
   if (bool1)
      cout << "INCORRECT: 8 is less than 0.\n";
   else
      cout << "CORRECT: 8 is not less than 0.\n";
      
   if (bool2)
      cout << "CORRECT: 8 is a multiple of 4.\n\n";
   else
      cout << "INCORRECT: 8 is not a multiple of 4.\n\n";
      
      
   // set the bools incorrectly to make sure the function is working properly
   bool1 = false; bool2 = true; 
     
   numberFacts(-10, bool2, bool1); // second test of numberFacts
   if (bool2)
      cout << "CORRECT: -10 is less than 0.\n";
   else
      cout << "INCORRECT: -10 is not less than 0.\n";

   if (bool1)
      cout << "INCORRECT: -10 is a multiple of 4.\n\n";
   else
      cout << "CORRECT: -10 is not a multiple of 4.\n\n";
      


   // Testing arrayInfo
   
   answer = arrayInfo(6,15,array); // first test of arrayInfo
   if (answer == -1)
      cout << "INCORRECT: 6 is an invalid array length.\n\n";
   else
      cout << "The number of the first 6 elements in the array that are within 10 of 15 is:\n"
             << "   " << answer << ". (Should be 2.)\n\n";
      
      
   answer = arrayInfo(4,0,array); // second test of arrayInfo
   if (answer == -1)
      cout << "INCORRECT: 4 is an invalid array length.\n\n";
   else
      cout << "The number of the first 4 elements in the array that are within 10 of 0 is:\n"
             << "   " << answer << ". (Should be 3.)\n\n";
   
   
   answer = arrayInfo(-5,10,array); // third test of arrayInfo
   if (answer == -1)
      cout << "CORRECT: -5 is an invalid array length.\n\n";
   else
      cout << "The number of the first -5 elements in the array that are within 10 of 10 is:\n"
             << "   " << answer << ". (0 or anything else here is INCORRECT.)\n\n";
             
			
   pause();
   return 0;
}