3. Prefix Sum

1.Range Sum Query - Immutable

2.Find Pivot Index

3.Running Sum of 1d Array

4.Subarray Sum Equals K

5.Product of Array Except Self

6.Contiguous Array

7.Continuous Subarray Sum

8.Subarray Sums Divisible by K

9.Range Sum Query 2D - Immutable

10.Car Pooling

11.Corporate Flight Bookings

12.Count Number of Nice Subarrays

13.Number of Submatrices That Sum to Target

14.Max Sum of Rectangle No Larger Than K