How can you determine the minimum cost if you know the maximum value in the array once all values are made equal?

If <code>cost2 > cost1 * 2</code>, we should just use <code>cost1</code> to change all the values to the maximum one.

Otherwise, it's optimal to choose the smallest two values and use <code>cost2</code> to increase both of them.

Since the maximum value is known, calculate the required increases to equalize all values, instead of naively simulating the operations.

There are not a lot of candidates for the maximum; we can try all of them and choose which uses the minimum number of operations.