#include<iostream>
#include<cstring>
#include<queue>
#include<stack>
#include<map>
#include<algorithm>
#include<string>
#include<set>
#include<cmath>
#include<cstdio>
using namespace std;
int num[100010];
int cha[100010];
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n;
        scanf("%d",&n);
        cha[1] = 0;
        cha[n + 1] = 0;
        cha[n + 2] = 0;
        long long ans = 0;
        int maxn = 0;
        int flag = 1;
        for(int i = 1 ; i <= n ; ++i)
        {
            scanf("%d",&num[i]);
            cha[i] = abs(num[i] - num[i - 1]);
        }
        cha[1] = 0;
        for(int i = 2 ; i <= n ; ++i)
        {
        if(maxn <= abs(num[i] - num[i - 1]))
          {
              maxn = abs(num[i] - num[i - 1]);
              flag = i;
          }
        }
        //cout<<maxn<<endl;
        for(int i = 3 ; i <= n; ++i)
        {
            if(i != flag  && i != flag + 1)
            ans += (abs(num[i] -num[i - 2]) > maxn ? abs(num[i] - num[i - 2]) : maxn);
            else{
                int tmp = 0;
                for(int j = 2 ; j <=  i- 2 ; ++j)
                {
                    if(cha[j] > tmp)
                        tmp = cha[j];
                }
                //cout<<tmp<<endl;
                for(int j = i + 2 ; j <= n ; ++j)
                {
                    if(cha[j] > tmp)
                        tmp = cha[j];
                }
                //cout<<"i = "<<i<<" "<<"tmp = "<<tmp<<endl;
                //cout<<abs(num[i] - num[i - 2])<<endl;
                tmp = max(tmp , abs(num[i] - num[i - 2]));
                //cout<<"tmp = "<<tmp<<endl;

                ans += tmp;

        }
        //cout<<ans<<endl;

        }
        //cout<<ans<<endl;
        if(flag != 2)
        {
            ans += maxn;
        }
        else
        {
            int lm = 0;
            for(int i = 3 ; i <= n ; ++i)
            {
                if(lm < cha[i])
                    lm = cha[i];

            }
            ans += lm;
        }
        if(flag != n)
        {
            ans += maxn;
        }
        else {
                int lm = 0;
            for(int i = 2 ; i < n ; ++i)
            {
                if(lm < cha[i])
                    lm = cha[i];

            }
        ans += lm;
        }
        cout<<ans<<endl;
    }
    return 0;
}