#891

Sum of Subsequence Widths

master · 1715 · lc hard +32 · verified · 40.3% accepted · 736 likes · top 20%

Description

Define the width of a sequence as the difference between its largest and smallest element. Given an integer array nums, sum the widths of every non-empty subsequence and return the result modulo 10⁹ + 7.

A subsequence preserves the original element order after some deletions (possibly none).

Example 1:

Input: nums = [2,1,3]

Output: 6

Explanation: The subsequences are [1], [2], [3], [2,1], [2,3], [1,3], [2,1,3].

The corresponding widths are 0, 0, 0, 1, 1, 2, 2.

The sum of these widths is 6.

Example 2:

Input: nums = [2]

Output: 0

Code

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class Solution:
    def sumSubseqWidths(self, nums: List[int]) -> int:

class Solution:
    def sumSubseqWidths(self, nums: List[int]) -> int: