Solution: Range Sum Query - Immutable

Statement

You are given an integer array, nums, and you need to handle multiple queries of the following type:

• Query: Calculate the sum of elements in nums between indices i and j (inclusive), where i <= j.

Implement the NumArray class to support the following operations efficiently:

• Constructor: Initializes the object with the integer array nums.

• sumRange(i, j): Returns the sum of the elements of nums between indices i and j (inclusive), i.e., the sum of nums[i] + nums[i + 1] + ... + nums[j].

Constraints:

• $1 \leq$ nums.length $\le 10^{}$ ...