Please solve the programming task below using a self-contained code snippet in a markdown code block.

Given an integer array nums, return the maximum difference between two successive elements in its sorted form. If the array contains less than two elements, return 0.
You must write an algorithm that runs in linear time and uses linear extra space.
 
Please complete the following python code precisely:
```python
class Solution:
    def maximumGap(self, nums: List[int]) -> int:
```