Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.
Example:
Given nums = [-2, 0, 3, -5, 2, -1]
sumRange(0, 2) -> 1
sumRange(2, 5) -> -1
sumRange(0, 5) -> -3
Note:
You may assume that the array does not change.There are many calls to sumRange function. class NumArray { public: vector<int>a; NumArray(vector<int>& nums) { a.resize(nums.size()+1,0); for(int i=0;i<nums.size();i++){ a[i+1]=nums[i]+a[i]; } } int sumRange(int i, int j) { return a[j+1]-a[i]; } }; /** * Your NumArray object will be instantiated and called as such: * NumArray* obj = new NumArray(nums); * int param_1 = obj->sumRange(i,j); */
