Code RoomSum of subarray minimums
HardPrep Room Coding #1501

Sum of subarray minimums

CodingAlgorithms & data structuresSenior–Staff~35 min

Given an array of integers, consider every contiguous subarray and take its minimum element. Return the sum of all those subarray minimums, modulo 1000000007. The array has at most 30000 elements, each between 1 and 30000.

Implement
sum_subarray_mins(arr: list[int]) → int
Examples
in[[3,1,2,4]]out17
What 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 35 min
InputExpectedGot
[[3,1,2,4]]17not run yetsample