Given an array of integers arr, find the sum of min(b), where b ranges over every (contiguous) subarray of arr. Since the answer may be large, return the answer modulo (10^9 + 7).
Example Inputs & Outputs
// Example 1:
Input: arr = [11, 81, 94, 43, 3]
Output: 444
// Example 2:
Input: arr = [2,2,2]
Output: 12
Constraints
- 1 <= arr.length <= 3 * 10^4
- 1 <= arr[i] <= 3 * 10^4
Edge Cases
- The array contains positive integers only.
- The result must be computed modulo (10^9 + 7).
- Single element array should return the element itself.
- Arrays with identical elements or repeating patterns may require careful handling to avoid overflow.
