Problem of The Day: Range Sum Query - Immutable

Problem Statement

leetcode problem link

My Solution

class NumArray:

    def __init__(self, nums: List[int]):
        self.prefix = []
        self.nums = nums[:]
        curr = 0
        for num in nums:
            curr += num
            self.prefix.append(curr)

    def sumRange(self, left: int, right: int) -> int:
        return self.prefix[right] - self.prefix[left] + self.nums[left]


# Your NumArray object will be instantiated and called as such:
# obj = NumArray(nums)
# param_1 = obj.sumRange(left,right)