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. Example: Given nums = [1, 3, 5]
sumRange(0, 2) -> 9 update(1, 2) sumRange(0, 2) -> 8 Note: The array is only modifiable by the update function. You may assume the number of calls to update and sumRange function is distributed evenly.
Binary indexed tree