Subarray minimum sum
Your task
Given an array of positive integers, return the sum of the minimum element over every contiguous subarray, modulo 1_000_000_007. There are n*(n+1)/2 subarrays. The array has at least one element.
Examples
sum_subarray_mins(arr: list[int]) -> intExample 1
Input
sum_subarray_mins([3, 1, 2, 4])Output
17