Package g3301_3400.s3351_sum_of_good_subsequences

Class Solution

java.lang.Object

g3301_3400.s3351_sum_of_good_subsequences.Solution

public class Solution
extends Object

3351 - Sum of Good Subsequences.

Hard

You are given an integer array nums. A good subsequence is defined as a subsequence of nums where the absolute difference between any two consecutive elements in the subsequence is exactly 1.

Return the sum of all possible good subsequences of nums.

Since the answer may be very large, return it modulo 109 + 7.

Note that a subsequence of size 1 is considered good by definition.

Example 1:

Input: nums = [1,2,1]

Output: 14

Explanation:

• Good subsequences are: [1], [2], [1], [1,2], [2,1], [1,2,1].
• The sum of elements in these subsequences is 14.

Example 2:

Input: nums = [3,4,5]

Output: 40

Explanation:

• Good subsequences are: [3], [4], [5], [3,4], [4,5], [3,4,5].
• The sum of elements in these subsequences is 40.

Constraints:

• 1 <= nums.length <= 105
• 0 <= nums[i] <= 105

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	sumOfGoodSubsequences(int[] nums)

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

sumOfGoodSubsequences

public int sumOfGoodSubsequences(int[] nums)