# FARAWAY - Editorial

Author: Nishank Suresh
Testers: Utkarsh Gupta, Jatin Garg
Editorialist: Nishank Suresh

1056

None

# PROBLEM:

Given an array A whose elements lie between 1 and M, define the distance of an array B (also with elements from 1 to M) to be \sum_{i=1}^N |A_i - B_i|. Compute the maximum possible distance of an array from A.

# EXPLANATION:

It is of course optimal to choose either B_i = 1 or B_i = M for each index i.

Note that this choice can be made independently for every index, so the solution is to simply take the best option for each one.

\sum_{i=1}^N \max(|A_i - 1|, |A_i - M|)

Note that the answer might not fit inside a 32-bit integer, so make sure to use an appropriate data type.

# TIME COMPLEXITY

\mathcal{O}(N) per test case.

# CODE:

Setter's code (Python)
for _ in range(int(input())):
n, m = map(int, input().split())
a = list(map(int, input().split()))
print(sum([max(x-1, m-x) for x in a]))