LeetCode 307. Range Sum Query - Mutable

'''
Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.

The update(i, val) function modifies nums by updating the element at index i to val.
'''
#764ms, 15.8MB
class NumArray(object):

    def __init__(self, nums):
        """
        :type nums: List[int]
        """
        self.nums = nums
     

    def update(self, i, val):
        """
        :type i: int
        :type val: int
        :rtype: None
        """
        self.nums[i] = val
     

    def sumRange(self, i, j):
        """
        :type i: int
        :type j: int
        :rtype: int
        """
        return sum(self.nums[i:j+1])


# Your NumArray object will be instantiated and called as such:
# obj = NumArray(nums)
# obj.update(i,val)
# param_2 = obj.sumRange(i,j)