1
class NumArray:
2
    nums = []
3
    s = 0
4
    l = 0
5

6
    def __init__(self, nums: List[int]):
7
        self.nums = nums
8
        self.s = sum(nums)
9
        self.l = len(nums)
10

11
    def update(self, index: int, val: int) -> None:
12
        self.s -= self.nums[index]
13
        self.nums[index] = val
14
        self.s += self.nums[index]
15

16
    def sumRange(self, left: int, right: int) -> int:
17
        if right - left > self.l // 2:
18
            ans = sum(self.nums[:left]) + sum(self.nums[right + 1 :])
19
            return self.s - ans
20
        else:
21
            return sum(self.nums[left : right + 1])