<p>You have an array <code>arr</code> of length <code>n</code> where <code>arr[i] = (2 * i) + 1</code> for all valid values of <code>i</code> (i.e., <code>0 <= i < n</code>).</p>
<p>In one operation, you can select two indices <code>x</code> and <code>y</code> where <code>0 <= x, y < n</code> and subtract <code>1</code> from <code>arr[x]</code> and add <code>1</code> to <code>arr[y]</code> (i.e., perform <code>arr[x] -=1 </code>and <code>arr[y] += 1</code>). The goal is to make all the elements of the array <strong>equal</strong>. It is <strong>guaranteed</strong> that all the elements of the array can be made equal using some operations.</p>
<p>Given an integer <code>n</code>, the length of the array, return <em>the minimum number of operations</em> needed to make all the elements of arr equal.</p>
