Need help calculating AVG of array values (minus the lowest) - c++

Question

So I have succeeded in confusing the hell out of myself in doing this. I am trying to get it to calculate the average of the weights entered into the array minus the lowest weight in the array. I'm using functions and somewhere along the line I confused myself with passing variables. It would be much appreciated if someone could give me a pointer and tell me if I'm way off base or not. Also how would I compare the values entered to a validation code? I have a line commented out that I was fiddling with, but never got working.
#include <iostream>
using namespace std;
int getWeight();
int findLowest(int arrayWeight);
double calcAverage(int weight);
bool askToContinue();
int main(){
do{
int weights = getWeight();
double lowest = findLowest(weights);
double average = calcAverage(weights);
}
while(askToContinue());
}
int getWeight() {
//Variables
int weights[5]; //array
double enterWeight = 0;
bool validAmount = false;
//For loop to gather info and place amounts in an array
cout << "Please enter the weights of the Tulbuks: " << endl;
cout << endl;
for (int counter = 0; counter < 5; counter++)
{
cin >> weights[counter];
//validAmount = (weights[index] > 5) && (weights[index] <= 500);
}
//Test to redisplay the entered information
cout << "Entered information: " << endl;
for(int index = 0; index < 5; index++)
{
cout << "\nThe entered information for Tulbuk #" << (index+1) << " is: " << weights[index];
cout << endl;
}
return -1;
/*
do
{
//Gather user input of amount of discs
cout << "How many discs do you wish to purchase?" << endl;
cout << "Please enter a number between 1 and 1,000,000" << endl;
cin >> weights;
cout << endl;
validAmount = (weights > 5) && (weights <= 500); // Tests if the amount entered is valid
if (!validAmount) // Prompts user amount entered was invalid
{
cout << "Invalid Amount. Please try again!" << endl;
}
}
while(!validAmount); // Runs loop again if the amount entered was not valid
return discs;
*/
}
int findLowest(int arrayWeight){
int lowWeight = 999999;
if(lowWeight > arrayWeight)
{
lowWeight = arrayWeight;
}
cout << arrayWeight;
system("PAUSE");
return arrayWeight;
}
double calcAverage(int weight){
//Variables
float avgWeight = 0;
int sumWeight = 0;
//Calls findLowest function to find lowest value
int lowestWeight = findLowest(weight);
//Calculates the average score
return weight;
}
bool askToContinue() // Asks the user if they want to continue. If yes, the loop restarts. If no, the program exits.
{
char userResponse = ' ';
bool validInput = false;
do
{
cout << endl;
cout << "Do you wish to continue?" << endl;
cout << "Enter y for 'yes' or n for 'no'" << endl;
cin >> userResponse;
validInput = (userResponse == 'y') || (userResponse == 'n');
if (!validInput)
{
cout << "Invalid response. Please try again!" << endl;
}
} while (!validInput);
return(userResponse == 'y');
}

Answer 1

You have a number of issues, the first being you need to understand the data types you're working with. You should declare the array once and then pass around a pointer to that array. These are a better set of declarations and for convenience set up a constant for the number of weights.
#include <iostream>
using namespace std;
const int numWeights = 5;
void getWeights(int weights[]);
int findLowest(int weights[]);
double calcAverage(int weights[]);
bool askToContinue();
int main() {
do {
int weights[numWeights];
getWeights(weights);
double average = calcAverage(weights);
cout << "Average: " << average << endl;
}
while (askToContinue());
}
getWeights was mostly ok, but use the passed in array.
void getWeights(int weights[]) {
double enterWeight = 0;
bool validAmount = false;
//For loop to gather info and place amounts in an array
cout << "Please enter the weights of the Tulbuks: " << endl;
cout << endl;
for (int counter = 0; counter < 5; counter++)
{
int weight;
cin >> weight;
while (weight < 5 || weight > 500)
{
cout << "Invalid weight, should be between 5 and 500" << endl;
cin >> weight;
}
weights[counter] = weight;
//validAmount = (weights[index] > 5) && (weights[index] <= 500);
}
//Test to redisplay the entered information
cout << "Entered information: " << endl;
for(int index = 0; index < 5; index++)
{
cout << "\nThe entered information for Tulbuk #" << (index+1) << " is: " << weights[index];
cout << endl;
}
}
For findLowest you need to keep track of the lowest value and the lowest index. By remembering the index of the lowest value, you will make the average easier. Your 99999 magic number isn't needed since we know there will always be a lowest value in your set. Start with index 0 and the first value. If you find something smaller, update the value and index. When the loop ends you'll have the first index of the lowest value. Note that the loops starts at 1 (the second item).
int findLowest(int weights[]) {
int lowestVal = weights[0];
int lowestIndex = 0;
for (int i=1; i<numWeights; i++) {
if (weights[i] < lowestVal) {
lowestVal = weights[i];
lowestIndex = i;
}
}
return lowestIndex;
}
For the average find the lowest index, add up all the weights but skip the index of the lowest, convert to double so you can get a good average and return the value.
double calcAverage(int weights[]) {
int lowestIndex = findLowest(weights);
int total = 0;
for (int i=0; i<numWeights; i++) {
if (i != lowestIndex) {
total += weights[i];
}
}
return (double)total/(double)(numWeights-1);
}