Range Sum Query - Mutable

Given an integer array nums , handle multiple queries of the following types:

Update the value of an element in nums .

Calculate the sum of the elements of nums between indices left and right inclusive where left <= right .

Implement the NumArray class:

NumArray(int[] nums) Initializes the object with the integer array nums .

void update(int index, int val) Updates the value of nums[index] to be val .

int sumRange(int left, int right) Returns the sum of the elements of nums between indices left and right inclusive (i.e. nums[left] + nums[left + 1] + ... + nums[right] ).