Help! problem with arrays

[juliani91]

A local zoo wants to keep track of how many pounds of food each of its three monkeys eats
each day during a typical week. Write a program that stores this information in a twodimensional
3 × 7 array, where each row represents a different monkey and each column
represents a different day of the week. The program should first have the user input the data
for each monkey. Then it should create a report that includes the following information:
• Average amount of food eaten per day by the whole family of monkeys.
• The least amount of food eaten during the week by any one monkey.
• The greatest amount of food eaten during the week by any one monkey.
Input Validation: Do not accept negative numbers for pounds of food eaten.

This part is the one that I don't understand: • The greatest amount of food eaten during the week by any one monkey.

This is so far what I have:

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
double totalAverage =0;
int monkey, day;


const int NUM_MONKEYS = 3;
const int NUM_DAYS = 7;
double average [NUM_MONKEYS][NUM_DAYS];
double highest, lowest;

cout << "Enter the amount of food in pounds eaten by the referred monkey.\n";

for (monkey = 0; monkey < NUM_MONKEYS; monkey++)
{
for (day = 0; day < NUM_DAYS; day++)
{
cout << "Monkey " << (monkey + 1) << ", "
<< "Day " << (day + 1) << ": ";
cin >> average [monkey][day];
while ((average [monkey][day] < 0))
{
cout << "Please enter positive values.\n";
cin >> average [monkey][day];
}
}
cout << endl;
}

for (monkey = 0; monkey < NUM_MONKEYS; monkey++)
{
for (day =0; day< NUM_DAYS; day++)

totalAverage += average [monkey][day]/ NUM_DAYS; // I don't get this part on how to get the average per day for each monkey.
}
//
for (monkey = 0; monkey < NUM_MONKEYS; monkey++)
{
for (day =0; day< NUM_DAYS; day++)
{
if ((average [monkey][day]) > highest)
highest = average [monkey][day];
}
//
}
for (monkey = 0; monkey < NUM_MONKEYS; monkey++)
{
for (day =0; day< NUM_DAYS; day++)
{
if ((average [monkey][day]) ) LOWEST Y PUES NOSE :S
lowest = average [monkey][day];
}
//
}
cout << fixed << showpoint << setprecision (2); DOUBLE
cout << "The average amount is: " << totalAverage << endl;
cout << "The highest amount is: " << highest << endl;
cout << "The lowest amount is: " << lowest << endl;


system ("PAUSE");
return 0;
}

[mlgoff]

Please make sure you code compiles and links before posting it, unless your question is about compiler/linker errors.

The code would not compile because of spurious text on lines 54 and 59.

A compiler warning was issued because you used the variable highest before initializing it. This could/should have caused all sorts of unexpected behavior at runtime.

In the future pelase use CODE BLOCKS ( like below) to preserve your formatting.

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
    double totalAverage =0;
    int monkey = 0, day = 0;
    int entered_value;


    const int NUM_MONKEYS = 3;
    const int NUM_DAYS = 7; 
    double average [NUM_MONKEYS][NUM_DAYS];
    double highest = 0, lowest;
    double monkeys[NUM_MONKEYS];

    memset(&monkeys[0], 0, sizeof(monkeys));
    memset(&average[0], 0, sizeof(average));

    cout << "Enter the amount of food in pounds eaten by the referred monkey.\n";

    for (monkey = 0; monkey < NUM_MONKEYS; monkey++)
    {
        for (day = 0; day < NUM_DAYS; day++)
        {
            cout << "Monkey " << (monkey + 1) << ", "
            << "Day " << (day + 1) << ": ";
            cin >> average [monkey][day];
            while ((average [monkey][day] < 0))
            {
                // Ensure that negative numbers are not accepted.
                entered_value = -1;
                while (entered_value < 0)
                {
                    cout << "Please enter positive values.\n";
                    cin >> entered_value;
                    if (entered_value > -1)
                    {
                        average [monkey][day] = entered_value; 
                    }
                    else
                    {
                        cout << "Negative values are not accepted.\n";
                    }
                }
            }
        }
        cout << endl;
    }

    for (monkey = 0; monkey < NUM_MONKEYS; monkey++)
    {
        // Get the total amount of food eaten during the week
        for (day =0; day< NUM_DAYS; day++)
        {
            // Store the total amount eaten by each monkey
            monkeys[monkey] += average [monkey][day];
        }
    }

    // Compute the average amount eaten by all monkeys each day.
    totalAverage = monkeys[0] + monkeys[1] + monkeys[2];
    totalAverage =  totalAverage / NUM_DAYS;

    // Compare the amounts eaten by each monkey to determine which one ate the most.
    for (monkey = 0; monkey < NUM_MONKEYS - 1; monkey++)
    {
        if (monkeys[monkey] > monkeys[monkey + 1])
        {
            if (monkeys[monkey] > highest)
            {
                highest = monkeys[monkey];
            }
        }
        else
        {
            highest = monkeys[monkey + 1];
        }
    }

    if (monkeys[0] < monkeys[1] && 
        monkeys[0] < monkeys[2])
    {
        lowest = monkeys[0];
    }
    else if (monkeys[1] < monkeys[2]) 
    {
        lowest = monkeys[1];
    }
    else
    {
        lowest = monkeys[2];
    }

    cout << fixed << showpoint << setprecision (2); // DOUBLE
    cout << "The average amount is: " << totalAverage << endl;
    cout << "The highest amount is: " << highest << endl;
    cout << "The lowest amount is: " << lowest << endl; 


    system ("PAUSE");
    return 0;
}

I added afew code comments to explain some of the changes I made. If you step through the code using a debugger, you shoudl be able to understand the logic and see how it works. In my experience you will learn more and have a better understanding that way.