LeetCode:Range Sum Query - Immutable

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Range Sum Query - Immutable
Total Accepted: 29091 Total Submissions: 118678 Difficulty: Easy

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) -> 1sumRange(2, 5) -> -1sumRange(0, 5) -> -3

Note:

1. You may assume that the array does not change.
2. There are many calls to sumRange function.

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Hide Tags Dynamic ProgrammingHide Similar Problems (M) Range Sum Query 2D - Immutable (M) Range Sum Query - Mutable (E) Maximum Size Subarray Sum Equals k

c++ code:

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

LeetCode:Range Sum Query - Immutable