Calculate the frequency of each number.

For each <code>x</code> in the range <code>[1, minimum_frequency]</code>, try to create groups with either <code>x</code> or <code>x + 1</code> indices assigned to them while minimizing the total number of groups.

For each distinct number, using its frequency, check that all its occurrences can be assigned to groups of size <code>x</code> or <code>x + 1</code> while minimizing the number of groups used.

To get the minimum number of groups needed for a number having frequency <code>f</code> to be assigned to groups of size <code>x</code> or <code>x + 1</code>, let <code>a = f / (x + 1)</code> and <code>b = f % (x + 1)</code>. <ul> <li>If <code>b == 0</code>, then we can simply create <code>a</code> groups of size <code>x + 1</code>.</li> <li>If <code>x - b <= a</code>, we can have <code>a - (x - b)</code> groups of size <code>x + 1</code> and <code>x - b + 1</code> groups of size <code>x</code>. So, in total, we have <code>a + 1</code> groups.</li> <li>Otherwise, it's impossible.</li> </ul>

The minimum number of groups needed for some <code>x</code> is the total minimized number of groups needed for each distinct number.

The answer is the minimum number of groups needed for each <code>x</code> in the range <code>[1, minimum_frequency]</code>.