#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <string>
#include <cmath>
using namespace std;
int a[100005];
int m[100005];
int main()
{

    int t;
    cin>>t;
    while(t--)
    {
        int n;
        scanf("%d",&n);
        for(int i=0;i<n;i++)
        {
            scanf("%d",&a[i]);
            if(i==0)
                continue;
            m[i] = a[i]-a[i-1];
        }
        int ma = 0,m0 = 0,mn = 0,mk;
        for(int i=1;i<n;i++)
        {
            if(ma<abs(m[i]))
            {
                ma = abs(m[i]);
                mk = i;
            }
        }
        for(int i=2;i<n;i++)
            m0 = max(m0,abs(m[i]));
        for(int i=1;i<n-1;i++)
            mn = max(mn,abs(m[i]));
        long long ans =0;
        for(int i=0;i<n;i++)
        {
            if(i==0)
                ans+=m0;
            else if(i==n-1)
                ans+=mn;
            else
            {
                if(abs(m[i]+m[i+1])>ma)
                    ans+=abs(m[i]+m[i+1]);
                else if(i==mk || i+1==mk)
                {
                    int temp = 0;
                    for(int j=1;j<n;j++)
                    {
                        if(j-1 == i)
                            temp = max(temp,abs(a[j]-a[j-2]));
                        else if(j==i)
                            continue;
                        else
                           temp = max(temp,abs(a[j]-a[j-1]));
                    }
                    ans+=temp;
                }
                else
                    ans+=ma;
            }
        }
        cout<<ans<<endl;
    }

    return 0;
}