Stick Lengths

Task:

There are $n$ sticks with some lengths. Your task is to modify the sticks so that each stick has the same length.

You can either lengthen and shorten each stick. Both operations cost $x$ where $x$ is the difference between the new and original length.

What is the minimum total cost?

Input

The first input line contains an integer $n$: the number of sticks.

Then there are $n$ integers: $p_1,p_2,\ldots,p_n$: the lengths of the sticks.

Output

Print one integer: the minimum total cost.

Constraints

• $1 \le n \le 2 \cdot 10^5$
  
• $1 \le p_i \le 10^9$
  

Solutions:

It's quite straightforward. The formula is $2^n$ where $n$ is input. The noticeable thing is moduling for $1e9+7$, and luckily function $pow$ can do it perfectly.

1def helper(n):
2    return pow(2,n,int(1e9+7))
3a=int(input())
4print(helper(a))
5 

Time complexity: $O(1)$

Space complexity: $O(1)$