Given a number N, the task is to find the sum of all the elements from all possible subsets of a set formed by first N natural numbers.
Example 1:
Input:
N = 2
Output:
6
Explanation:
Possible subsets are {{1}, {2}, {1, 2}}.
Sum of elements in the subsets is
1 + 2 + 1 + 2 = 6.
Example 2:
Input:
N = 3
Output:
24
Explanation:
Possible subsets are
{{1},{2},{3},{1,2},{2,3},{1,3},{1,2,3}}.
Sum of elements in the subsets is
1+2+3+1+2+2+3+1+3+1+2+3 = 24
Your Task:
You don't need to read input or print anything. Your task is to complete the function sumOfSubsets() which takes an integer N as an input parameter and return the sum of all the elements from all possible subsets of a set formed by first N natural numbers.
Expected Time Complexity: O(logN)
Expected Auxiliary Space: O(1)
Constraints:
1 <= N <= 50

见题面

见题面