1
class Solution:
2
    def waysToMakeFair(self, nums: List[int]) -> int:
3
        if len(nums) == 1:
4
            return 1
5

6
        if len(nums) == 2:
7
            return 0
8

9
        prefixEven = sum(nums[2::2])
10
        prefixOdd = sum(nums[1::2])
11
        result = 0
12

13
        if prefixEven == prefixOdd and len(set(nums)) == 1:
14
            result += 1
15

16
        for i in range(1, len(nums)):
17
            if i == 1:
18
                prefixOdd, prefixEven = prefixEven, prefixOdd
19

20
            if i > 1:
21
                if i % 2 == 0:
22
                    prefixEven -= nums[i - 1]
23
                    prefixEven += nums[i - 2]
24

25
                else:
26
                    prefixOdd -= nums[i - 1]
27
                    prefixOdd += nums[i - 2]
28

29
            if prefixOdd == prefixEven:
30
                result += 1
31

32
        return result