Class Solution
java.lang.Object
g0801_0900.s0891_sum_of_subsequence_widths.Solution
public class Solution
extends java.lang.Object
891 - Sum of Subsequence Widths.
Hard
The width of a sequence is the difference between the maximum and minimum elements in the sequence.
Given an array of integers nums
, return the sum of the widths of all the non-empty subsequences of nums
. Since the answer may be very large, return it modulo 109 + 7
.
A subsequence is a sequence that can be derived from an array by deleting some or no elements without changing the order of the remaining elements. For example, [3,6,2,7]
is a subsequence of the array [0,3,1,6,2,2,7]
.
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
Constraints:
1 <= nums.length <= 105
1 <= nums[i] <= 105
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Constructor Summary
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Method Summary
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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Solution
public Solution()
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Method Details
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sumSubseqWidths
public int sumSubseqWidths(int[] nums)
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