Leetcode 303 Solution

This article provides solution to leetcode question 303 (range-sum-query-immutable)

https://leetcode.com/problems/range-sum-query-immutable

Solution

class NumArray {
    vector<int> sums;
public:
    NumArray(vector<int> &nums) {
        sums.resize(nums.size());

        int sum = 0;

        for (int i = 0; i < nums.size(); i++)
        {
            sum += nums[i];
            sums[i] = sum;
        }
    }

    int sumRange(int i, int j) {
        if (i == 0)
            return sums[j];
        else
            return sums[j] - sums[i - 1];
    }
};


// Your NumArray object will be instantiated and called as such:
// NumArray numArray(nums);
// numArray.sumRange(0, 1);
// numArray.sumRange(1, 2);