Package g0901_1000.s0907_sum_of_subarray_minimums

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    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 <code>10<sup>9</sup> + 7</code>.

    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:

    • <code>1 <= arr.length <= 3 * 10<sup>4</sup></code>

    • <code>1 <= arri<= 3 * 10<sup>4</sup></code>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Integer sumSubarrayMins(IntArray arr)

      • Methods inherited from class java.lang.Object

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