Simple Python Solution - O(n) 
IntuitionApproachHashmap to store the occurance of the numbers and remember to add back the assumed outlier after the checkComplexity
Time complexity:

Space co
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->
Hashmap to store the occurance of the numbers and remember to add back the assumed outlier after the check
# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```python []
class Solution(object):
    def getLargestOutlier(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        # sum of special values = n, one sum = n, one outlier = a, we want to max a
        total = sum(nums)
        
        diction = {}
        number = set(nums)

        for num in nums:
            if num not in diction:
                diction[num] = 1
            else:
                diction[num] += 1

        res = -1001
        for num in nums:
            # assume this num is outlier, then check the rest fit into the condition or not.
            tempsumtwo = total - num
            if tempsumtwo % 2 == 1:
                continue
            else:
                tempsum = tempsumtwo // 2
                if tempsum in diction:
                    diction[num] -= 1
                    if diction[tempsum] > 0 and res < num:
                        res = num
                    diction[num] += 1
                else:
                    continue
        print(total, res)
        return res
                    

        
```
['Python']