#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cctype>
#include <cmath>
#include <cstdlib>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <vector>
#define PI acos(-1.0)
#define ll long long
#define INF 0x3f3f3f3f
#define eps 1e-6
#define rep(i, a, n) for(int (i) = (a); (i) <= (n); (i)++)
#define per(i, n, a) for(int (i) = (n); (i) >= (a); (i)--)
#define For(i, a, n) for(int (i) = (a); (i) < (n); (i)++)
#define mset(x) memset((x), 0, sizeof((x)))
#define meset(x) memset((x), -1, sizeof((x)))
#define pb push_back
#define mp make_pair
#define sf scanf
#define pf printf
#pragma comment(linker, "/STACK:1024000000,1024000000")
#define mod 1000000007
using namespace std;
int a[100004];
int main()
{
    int re;
    sf("%d", &re);
    while(re--)
    {
        int n;
        sf("%d", &n);
        int bigest = -1, cnt, index = -1;
        ll sum = 0;
        for(int i = 0; i < n; i++)
        {
            sf("%d", &a[i]);
            if(i < 1)
                continue;
            if(abs(a[i] - a[i - 1]) > bigest)
            {
                index = i;
                bigest = abs(a[i] - a[i - 1]);
            }
        }
        int tmp = -1;
        if(index != 0 && index - 1 != 0)
        {
            for(int i = 2; i < n; i++)
            {
                if(abs(a[i] - a[i - 1]) > tmp)
                    tmp = abs(a[i] - a[i - 1]);
            }
            sum += tmp;
        }
        tmp = -1;
        if(index != n - 1 && index - 1 != n - 1)
        {
            for(int i = 1; i < n - 1; i++)
            {
                if(abs(a[i] - a[i - 1]) > tmp)
                    tmp = abs(a[i] - a[i - 1]);
            }
            sum += tmp;
        }
        tmp = -1;
        for(int i = 1; i < n; i++)
        {
            if(i == index - 1)
                continue;
            else if(i == index)
            {
                if(index - 2 >= 0)
                {
                    tmp = max(tmp, abs(a[i] - a[i - 2]));
                }
                else
                    continue;
            }
            else
                tmp = max(tmp, abs(a[i] - a[i - 1]));
        }
        sum += tmp;
        tmp = -1;
        for(int i = 1; i < n; i++)
        {
            if(i == index)
                continue;
            else if(i == index + 1)
            {
                tmp = max(tmp, abs(a[i] - a[i - 2]));
            }
            else
                tmp = max(tmp, abs(a[i] - a[i - 1]));
        }
        sum += tmp;
        for(int i = 2; i < n; i++)
        {
            if(i == index || i == index + 1)
                continue;
            if(abs(a[i] - a[i - 2]) > bigest)
                sum += abs(a[i] - a[i - 2]);
            else
                sum += bigest;
        }
        pf("%I64d\n", sum);
    }
}