Far Away Codechef Solution

Problem

Chef has an array $A$ of size $N$ and an integer $M$, such that 1 \leq A_i \leq M1≤Ai​≤M for every $1\le i\le N$.

The distance of an array $B$ from array $A$ is defined as:

Chef wants an array $B$ of size $N$, such that 1 \le B_i \le M1≤Bi​≤M and the value $d(A,B)$ is as large as possible, i.e, the distance of $B$ from $A$ is maximum.

Find the maximum distance for any valid array $B$.

Note: $|X|$ denotes the absolute value of an integer $X$. For example, $|-4|=4$ and $|7|=7$.

Input Format

• The first line of input will contain a single integer $T$, denoting the number of test cases.
• Each test case consists of two lines of input.
  • The first line of each test case contains two space-separated integers $N$ and $M$ — the length of array $A$ and the limit on the elements of $A$ and $B$.
  • The second line contains $N$ space-separated integers A_1, A_2, \ldots, A_NA1​,A2​,…,AN​.

Output Format

For each test case, output on a new line the maximum distance of an array from $A$.

Constraints

Sample 1:

4
2 6
3 5
4 1
1 1 1 1
5 7
2 3 4 5 6
7 24
23 7 6 16 12 4 24

7
0
21
127

Explanation:

Test case $1$: The array having maximum distance from $A$ is $B=[6,1]$. Thus the distance is $|3-6|+|5-1|=3+4=7$.

Test case $2$: The only array possible is $B=[1,1,1,1]$. The distance of this array from $A$ is $0$.

Test case $3$: One of the possible arrays having maximum distance from $A$ is $B=[7,7,1,1,1]$. Thus the distance is $|2-7|+|3-7|+|4-1|+|5-1|+|6-1|=5+4+3+4+5=21$.