<p>You are given the array <code>nums</code> consisting of <code>n</code> positive integers. You computed the sum of all non-empty continuous subarrays from the array and then sorted them in non-decreasing order, creating a new array of <code>n * (n + 1) / 2</code> numbers.</p>

<p><em>Return the sum of the numbers from index </em><code>left</code><em> to index </em><code>right</code> (<strong>indexed from 1</strong>)<em>, inclusive, in the new array. </em>Since the answer can be a huge number return it modulo <code>10<sup>9</sup> + 7</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4], n = 4, left = 1, right = 5
<strong>Output:</strong> 13 
<strong>Explanation:</strong> All subarray sums are 1, 3, 6, 10, 2, 5, 9, 3, 7, 4. After sorting them in non-decreasing order we have the new array [1, 2, 3, 3, 4, 5, 6, 7, 9, 10]. The sum of the numbers from index le = 1 to ri = 5 is 1 + 2 + 3 + 3 + 4 = 13. 
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4], n = 4, left = 3, right = 4
<strong>Output:</strong> 6
<strong>Explanation:</strong> The given array is the same as example 1. We have the new array [1, 2, 3, 3, 4, 5, 6, 7, 9, 10]. The sum of the numbers from index le = 3 to ri = 4 is 3 + 3 = 6.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4], n = 4, left = 1, right = 10
<strong>Output:</strong> 50
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>n == nums.length</code></li>
	<li><code>1 &lt;= nums.length &lt;= 1000</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 100</code></li>
	<li><code>1 &lt;= left &lt;= right &lt;= n * (n + 1) / 2</code></li>
</ul>

class FenwickTree
{
    public:
    vector<int> tree;
    int sz = 0;
    FenwickTree(int n)
    {
        tree.resize(n + 1, 0);
        sz = n + 1;
    }

    void update(int index, int value)
    {
        index++;
        while(index < sz)
        {
            tree[index] += value;
            index += index & (-index);
        }
    }

    long long sum(int index)
    {
        index++;
        long long sum = 0;
        while(index > 0)
        {
            sum += tree[index];
            index = index & (index - 1);
        }
        return sum;
    }

    long long range(int i, int j)
    {
        return sum(j) - sum(i - 1);
    }
};
class Solution {
public:
    int rangeSum(vector<int>& nums, int n, int left, int right) {
        int m = (n * (n + 1)) / 2;
        FenwickTree arr(n);
        int v[m];
        memset(&v, m, 0);
        int k = 0;
        for(int i = 0; i < n; i++)
        {
            arr.update(i, nums[i]);
        }
        for(int i = 0; i < n; i++)
        {
            for(int j = i; j < n; j++)
            {
                v[k++] = arr.range(i, j);
            }
        }
        sort(v, v + m);
        int mod = 1e9 + 7;
        long long ans = 0;
        /* for(int i = 0; i < m; i++)
        cout<<v[i]<<" ";
        cout<<endl; */
        left--;
        right--;
        while(left <= right)
        {
            ans = ((ans % mod) + v[left++]) % mod;
        }
        return ans;
    }
};
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