Thread: test scores(avg, highest, lowest...)

Watch what your code is doing and you can see why it's tweaking out. You should always try and trace what's happening, as each line of code runs, to spot where you've gone wrong.

Code:

// This program will read in a group of test scores( positive integers from 1 to 100)
// from the keyboard and then calculates and outputs  the average score
// as well as the highest and lowest score. There will be a maximum of 100 scores.


#include <iostream>
using namespace std;



float findAverage (int [], int);  // finds average of all grades
int   findHighest (int [], int&);  // finds highest of all grades
int   findLowest  (int [], int&);  // finds lowest of all grades

int main()

{
    const int SIZE=100;
    int  grades[SIZE];		// == ???
    int  numberOfGrades; 	// == ???
    int pos; 				// == ???
	int size;				// == ???
	float avgOfGrades;		// == ???
	int highestGrade;		// == ???
	int lowestGrade;		// == ???

	// Read the values into the array
	// pos == 0, grades[0] == ???
	pos = 0; 
	cout << "Please input a grade from 1 to 100, (or -99 to stop)" << endl;
	// Fake input: 1
	cin  >> grades[pos];
	// pos == 0, grades[0] == 1

	// 1: pos == 0, grades[0] == 1, grades[0] != -99
	// 2: pos == 0, grades[0] == 75, grades[0] != -99
	// 3: pos == 0, grades[0] == 84, grades[0] != -99
	// 4: pos == 0, grades[0] == 99, grades[0] != -99
	// 5: pos == 0, grades[0] == 100, grades[0] != -99
	// 6: pos == 0, grades[0] == -99, grades[0] == -99 --->
	while (grades[pos] != -99)
	{
		// 1: (pos + 1) == 1, grades[1] == ???
		// 2: (pos + 1) == 1, grades[1] == ???
		// 3: (pos + 1) == 1, grades[1] == ???
		// 4: (pos + 1) == 1, grades[1] == ???
		// 5: (pos + 1) == 1, grades[1] == ???
		cout << "enter test score number " << (pos + 1) << ":";
		// 1: Fake input 75
		// 2: Fake input 84
		// 3: Fake input 99
		// 4: Fake input 100
		// 5: Fake input -99
		cin >> grades[pos];
		// 1: pos == 0, grades[0] == 75
		// 2: pos == 0, grades[0] == 84
		// 3: pos == 0, grades[0] == 99
		// 4: pos == 0, grades[0] == 100
		// 5: pos == 0, grades[0] == -99
	}

	// --->
	// pos == 0, grades[0] == -99, numberOfGrades == -99
	numberOfGrades = grades[pos];  // Fill blank with appropriate identifier

	// call to the function to find average
	// avgOfGrades == ???
	// avgOfGrades == findAverage(grades, -99) --->
	avgOfGrades = findAverage(grades, numberOfGrades);
	// --->
	// avgOfGrades == 0
	cout << endl << "The average of all the grades is " << avgOfGrades << endl;

	//  Fill in the call to the function that calculates highest grade
	// highestGrade == ???
	// highestGrade == findHighest(grades, -99) --->
	highestGrade = findHighest(grades, size);
	// --->
	// highestGrade == ???
	cout << endl << "The highest grade is " << highestGrade << endl;

	// Fill in the call to the function that calculates lowest grade
	// lowestGrade == ???
	// lowestGrade == findLowest(grades, -99) --->
	lowestGrade = findLowest(grades, size);
    // Fill in code to write the lowest to the screen
    // --->
    // lowestGrade == ???
	cout << endl << "The highest grade is " << lowestGrade << endl;

	return 0; // ---> (0)
}

//****************************************************************************
//                                 findAverage
//
// task:          This function receives an array of integers and its size.
//                It finds and returns the average of the numbers in the array
// data in:       array of floating point numbers
// data returned: avarage of the numbers in the array
//
//****************************************************************************

float findAverage (int array[], int size)
{  
	// --->
	float sum = 0;   // holds the sum of all the numbers

	// for (pos = 0, pos < -99; pos++) --->
    for (int pos = 0; pos < size; pos++)
		sum = sum + array[pos];

	// --->
	// sum == 0, size == -99
    return (sum / size);  // --->
          
}

//****************************************************************************
//                                 findHighest
//
// task:          This function receives an array of integers and its size.
//                It finds and returns the highest value of the numbers in
//                the array
// data in:       array of floating point numbers
// data returned: highest value of the numbers in the array
//
//****************************************************************************

int   findHighest (int array[], int& size)
{
   // Fill in the code for this function
   // --->
   // array == grades, size == -99, SIZE == 100
	const int SIZE=100;
	int highest;			// == ???
	int grades[SIZE];		// == ???
	// grades[0] == ???, highest == ???
	highest = grades[0];	
	
	// for (pos == 1, pos < 100; pos++)
	for (int pos = 1; pos < SIZE; pos++)
	{
		// grades[pos] == ???, highest == ???
	   if (grades[pos] > highest)
		// highest == ???
		  highest = grades[pos];
		  // etc...
	}
	
	// highest == ???
	return highest;	// --->
}


//****************************************************************************
//                                 findLowest
//
// task:          This function receives an array of integers and its size.
//                It finds and returns the lowest value of the numbers in 
//                the array
// data in:       array of floating point numbers
// data returned: lowest value of the numbers in the array
//
//****************************************************************************

int   findLowest(int array[], int& size)
{
	// --->
   // Fill in the code for this function
	const int SIZE=100;
	int lowest;			// == ???
	int grades[SIZE];	// == ???	
	// grades[0] == ???, lowest == ???
	lowest = grades[0];
	
	// for (pos == 1; pos < 100; pos++)
	for (int pos = 1; pos < SIZE; pos++)
	{
		// grades[pos] == ???, lowest == ???
	   if (grades[pos] < lowest)
			// grades[pos] == ???, lowest == ???
		  lowest = grades[pos];
		  // etc...
	}
	
	// lowest == ???
	return lowest; // --->

}