Given an array arr[] of N integers, the task is to find the sum of values of all possible non-empty subsets of array the given array.
Examples:
Input: arr[] = {2, 3}
Output: 10
All non-empty subsets are {2}, {3} and {2, 3}
Total sum = 2 + 3 + 2 + 3 = 10
Input: arr[] = {2, 1, 5, 6}
Output: 112
Approach: It can be observed that when all the elements are added from all the possible subsets then each element of the original array appears in 2(N – 1) times. Which means contribution of any element arr[i] in the final answer will be arr[i] * 2(N – 1). So, the required answer will be (arr[0] + arr[1] + arr[2] + … + arr[N – 1]) * 2(N – 1).
Below is the implementation of the above approach:
C++
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // Function to return the required sum int sum( int arr[], int n) { // Find the sum of the array elements int sum = 0; for ( int i = 0; i < n; i++) { sum += arr[i]; } // Every element appears 2^(n-1) times sum = sum * pow (2, n - 1); return sum; } // Driver code int main() { int arr[] = { 2, 1, 5, 6 }; int n = sizeof (arr) / sizeof ( int ); cout << sum(arr, n); return 0; } |
Java
// Java implementation of the approach class GFG { // Function to return the required sum static int sum( int arr[], int n) { // Find the sum of the array elements int sum = 0 ; for ( int i = 0 ; i < n; i++) { sum += arr[i]; } // Every element appears 2^(n-1) times sum = sum * ( int )Math.pow( 2 , n - 1 ); return sum; } // Driver code public static void main (String[] args) { int arr[] = { 2 , 1 , 5 , 6 }; int n = arr.length; System.out.println(sum(arr, n)); } } // This code is contributed by AnkitRai01 |
Python3
# Python3 implementation of the approach # Function to return the required sum def sum ( arr, n): # Find the sum of the array elements sum = 0 for i in arr : sum + = i # Every element appears 2^(n-1) times sum = sum * pow ( 2 , n - 1 ) return sum # Driver code arr = [ 2 , 1 , 5 , 6 ] n = len (arr) print ( sum (arr, n)) # This code is contributed by Arnab Kundu |
C#
// C# implementation of the approach using System; class GFG { // Function to return the required sum static int sum( int [] arr, int n) { // Find the sum of the array elements int sum = 0; for ( int i = 0; i < n; i++) { sum += arr[i]; } // Every element appears 2^(n-1) times sum = sum * ( int )Math.Pow(2, n - 1); return sum; } // Driver code public static void Main () { int [] arr = { 2, 1, 5, 6 }; int n = arr.Length; Console.WriteLine(sum(arr, n)); } } // This code is contributed by CodeMech |
Javascript
<script> // javascript implementation of the approach // Function to return the required sum function sum(arr, n) { // Find the sum of the array elements var sum = 0; for (i = 0; i < n; i++) { sum += arr[i]; } // Every element appears 2^(n-1) times sum = sum * parseInt(Math.pow(2, n - 1)); return sum; } // Driver code var arr = [ 2, 1, 5, 6 ]; var n = arr.length; document.write(sum(arr, n)); // This code is contributed by Amit Katiyar </script> |
112
Time Complexity: O(n)
Auxiliary Space: O(1)
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