Preprocess Immutable Inclusive Array Range Sums
Company: Google
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Other
### Problem
Implement `NumArray(vector<int>& nums)` and sumRange(left,right). The array remains unchanged after construction; each query returns the sum over the zero-based inclusive interval left..right. Preserve the stateful constructor/query API.
```cpp
class NumArray {
public:
NumArray(vector<int>& nums);
int sumRange(int left, int right);
};
```
### Examples
```text
NumArray([4,-2,7]); sumRange(0,1) -> 2; sumRange(1,2) -> 5
NumArray([-5]); sumRange(0,0) -> -5
```
### Constraints
- Length is 1 through 10000; values lie in [-100000,100000].
- 0 <= left <= right < length.
- At most 10000 sumRange calls occur.
Overview: Preprocess Immutable Inclusive Array Range Sums. Implement NumArray(vector int & nums) and sumRange(left,right). The array remains unchanged after construction; each query returns the sum over the zero-based i