Using dynamic memory allocation to add elements into an array
<p>I'm supposed to write some code to ask the user to enter an array (1.3 4 5.2 16.3 9.99 7.21 4.5 7.43 11.21 12.5).</p>

<p>After that, I create a new array with a bigger size (double the size), copy all the elements from the old array to the new one, then ask the user to continue to enter 5 more elements to the new array: 1.5 4.5 9.5 16.5 7.5 11.5, and then print out the final array (15 elements).</p>

<p>Here is my code:</p>

<pre><code>#include "stdafx.h"
#include &lt;iostream&gt;
#include &lt;string&gt;

using namespace std;

double* read_data(int&amp; size) 
{
    int max = 10;         
    double* a = new double[max];  // allocated on heap
    size = 0;

    cout &lt;&lt; "Enter the array: " &lt;&lt; endl;
    while (cin &gt;&gt; a[size]) 
    {
        size++;
    }
    if (size &gt;= max) 
    {
        double* temp = new double[max * 2];
        for (int i = 0; i &lt; size; i++) 
        {
            temp[i] = a[i];       
        }
        delete[] a;             
        a = temp;   
        max = max * 2;  
    }
    return a;
}

int main () 
{
    int input1, input2, input3, input4, input5;

    int size = 0;
    double* arr = read_data(size);

    cout &lt;&lt; "Please enter 5 more elements: " &lt;&lt; endl;
    cin &gt;&gt; input1 &gt;&gt; input2 &gt;&gt; input3 &gt;&gt; input4 &gt;&gt; input5;
    arr[10] = input1;
    arr[11] = input2;
    arr[12] = input3;
    arr[13] = input4;
    arr[14] = input5;

    cout &lt;&lt; "The final array is: " &lt;&lt; endl;

    for (int i = 0; i &lt; 15; i++)
    {
        cout &lt;&lt; arr[i];
    }

    system("pause");
    return 0;
}
</code></pre>

<p>It doesn't let me enter 5 more elements and I don't know why.
Please help.</p>