# Leetcode 303 - Range sum query - Immutable

Note:

• Lots of calls will be made, it’s not clever to calculate each call.
• Make an array for sum[0, i]
• Do deduction betwen arr[right] - arr[left - 1].
• Make arr[left - 1] === 0 when left - 1 < 0.

Question:

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

• 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.
• 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]).

Example:

Code: