Subarray minimum sum
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.
Implement
sum_subarray_mins(arr: list[int]) → intExamples
in
[[3,1,2,4]]out17What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 30 min
solution.py
InputExpectedGot
[[3,1,2,4]]17not run yetsample