303. Range Sum Query - Immutable

class NumArray { private: vector<int> number; public: NumArray(vector<int> &nums) { for(int i=1;i<nums.size();i++) { nums[i]+=nums[i-1]; } number=nums; } int sumRange(int i, int j) { if(i==0) return number[j]; else return number[j]-number[i-1]; } }; // Your NumArray object will be instantiated and called as such: // NumArray numArray(nums); // numArray.sumRange(0, 1); // numArray.sumRange(1, 2);