java.lang.Object
g3001_3100.s3082_find_the_sum_of_the_power_of_all_subsequences.Solution

public class Solution extends java.lang.Object
3082 - Find the Sum of the Power of All Subsequences.

Hard

You are given an integer array nums of length n and a positive integer k.

The power of an array of integers is defined as the number of subsequences with their sum equal to k.

Return the sum of power of all subsequences of nums.

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

Example 1:

Input: nums = [1,2,3], k = 3

Output: 6

Explanation:

There are 5 subsequences of nums with non-zero power:

  • The subsequence [ 1 , 2 , 3 ] has 2 subsequences with sum == 3: [1,2,3] and [1,2,3].
  • The subsequence [ 1 ,2, 3 ] has 1 subsequence with sum == 3: [1,2,3].
  • The subsequence [1, 2 , 3 ] has 1 subsequence with sum == 3: [1,2,3].
  • The subsequence [ 1 , 2 ,3] has 1 subsequence with sum == 3: [1,2,3].
  • The subsequence [1,2, 3 ] has 1 subsequence with sum == 3: [1,2,3].

Hence the answer is 2 + 1 + 1 + 1 + 1 = 6.

Example 2:

Input: nums = [2,3,3], k = 5

Output: 4

Explanation:

There are 3 subsequences of nums with non-zero power:

  • The subsequence [ 2 , 3 , 3 ] has 2 subsequences with sum == 5: [2,3,3] and [2,3,3].
  • The subsequence [ 2 ,3, 3 ] has 1 subsequence with sum == 5: [2,3,3].
  • The subsequence [ 2 , 3 ,3] has 1 subsequence with sum == 5: [2,3,3].

Hence the answer is 2 + 1 + 1 = 4.

Example 3:

Input: nums = [1,2,3], k = 7

Output: 0

**Explanation: **There exists no subsequence with sum 7. Hence all subsequences of nums have power = 0.

Constraints:

  • 1 <= n <= 100
  • 1 <= nums[i] <= 104
  • 1 <= k <= 100
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    int
    sumOfPower(int[] nums, int k)
     

    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

    • sumOfPower

      public int sumOfPower(int[] nums, int k)