Package g0901_1000.s0907_sum_of_subarray_minimums

Class Solution

java.lang.Object
g0901_1000.s0907_sum_of_subarray_minimums.Solution
public class Solution extends java.lang.Object
907 - Sum of Subarray Minimums.

Medium

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 109 + 7.

Example 1:

Input: arr = [3,1,2,4]

Output: 17

Explanation:

Subarrays are [3], [1], [2], [4], [3,1], [1,2], [2,4], [3,1,2], [1,2,4], [3,1,2,4].

Minimums are 3, 1, 2, 4, 1, 1, 2, 1, 1, 1. Sum is 17.

Example 2:

Input: arr = [11,81,94,43,3]

Output: 444

Constraints:

  • 1 <= arr.length <= 3 * 104
  • 1 <= arr[i] <= 3 * 104

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    sumSubarrayMins(int[] arr)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • sumSubarrayMins

      public int sumSubarrayMins(int[] arr)