C++ int Array not returning largest value

[firebird102085]

Hello All,

First - I am just a beginner at this (just started studying C++ this semester) so I am lost somewhat sometimes and I think I am making good headway with my first array, but, I can not get it to return any output in my console window. I'm somewhat positive in the way the code has written as I have debugged all the syntax errors. I cannot simply get the program to read the output or display an output. I was hoping you might have some suggestions. Also, could you please tell me what may need to be fixed in this array.

Problem:

Write a C++ function, lastLargestIndex that takes as parameters an int array and its size and returns the index of the last occurrence of the largest element in the array. Also, write a program to test your function.

Code Solution:

#include <iostream>

using namespace std;
//*****************************DECLARATION ARRAY*******************************************

int lastLargestIndex(int [], int);

void main()

{
    int arr[15] = {5,198,76,9,4,2,15,8,21,34,99,3,6,13,61,};
    int location;
    location = lastLargestIndex(arr, 15);
        cout << "The last largest index is:" << location << endl;

}

//*****************************LOOPS INTO FOR LARGEST OCCURANCE*******************************************

int lastLargestIndex(int arr[], int size)

{
    int lastLargestIndex = 15;
    int tem = arr[0];
    int i;
    for(i = 0; i < size; i++)
    {
        if (arr[i] > tem)
        {
            lastLargestIndex = i;
            tem = arr[i];
        }
    }
    //*****************************RETURNS TO THE LARGEST NUMBER*******************************************
    system ("pause");
    return lastLargestIndex;
}

Thank You,
Neil

[Moschops]

The for loop only executes ONCE.

[nullptr]

You've almost got it right.
Note that it should be int main() and pausing at line 35 achieves nothing.

Here's your code with some corrections.

#include <iostream>

using namespace std;

int lastLargestIndex(int [], int);

int main()
{
    int arr[15] = {5,198,76,9,4,2,15,8,21,34,99,3,198,13,61,};
    int location = lastLargestIndex(arr, 15);

    if (location != -1)
        cout << "The last largest index is: " << location << endl;

    // pause to read the output
    cout << "\npress Enter to exit...";
    cin.get();

    return 0;
}

int lastLargestIndex(int arr[], int size)
{
    if (size == 0)
        return -1;

    if (size == 1)
        return 0;

    // set variables to the first index
    int lastLargestIndex = 0;
    int tem = arr[0];

    // start the loop from the 2nd index (1)
    for (int i = 1; i < size; ++i)
    {
        if (arr[i] >= tem) // note >= so we get the last occurrence
        {
            lastLargestIndex = i;
            tem = arr[i];
        }
    }

    return lastLargestIndex;
}

[Moschops]

Oop. Ignore my post above. I read your code too fast before running for lunch and didn't check it.

[mrnutty]

Seems to work http://codepad.org/Y6oXRlOf

[nullptr]

re: firstPerson's code

int lastLargestIndex(int arr[], int size)

{
    int lastLargestIndex = 0;
    int tem = arr[0];
    int i;
    for(i = 0; i < size; i++)
    {
        if (arr[i] > tem)
        {
            lastLargestIndex = i;
            tem = arr[i];
        }
    }
    return lastLargestIndex;
}

Consider if the array has duplicate entries.

int arr[15] = {5,11111,76,9,4,2,15,8,21,34,99,3,6,13,11111};

Using (arr[i] > tem) will return the last highest index being index 1, because the value of arr[14] is not greater than the value of arr[1].

That's why you need if (arr[i] >= tem)

[mrnutty]

@nullptr, nvmd didn't realize the 'last' word in 'lastLargestIndex'