#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
#include <map>
#include <iomanip>
typedef long long ll;
using namespace std;
const ll N = 2e5+10;  // limit for array size
int n;  // array size
ll t[2 * N];

void build()    // build the tree
{
    for (ll i = n - 1; i > 0; --i) t[i] = max(t[i<<1], t[i<<1|1]);
}

void modify(ll p, ll value)    // set value at position p
{
    for (t[p += n] = value; p > 1; p >>= 1) t[p>>1] = max(t[p], t[p^1]);
}

ll query(ll l, ll r)    // sum on llerval [l, r)
{
    ll res = 0;
    for (l += n, r += n; l < r; l >>= 1, r >>= 1)
    {
        if (l&1) res =max(res, t[l++]);
        if (r&1) res =max(res,t[--r]);
    }
    return res;
}

ll a[N];
ll b[N];
int main()
{
    int T;
    scanf("%d",&T);
    while (T--)
    {
        scanf("%d", &n);
        int i;
        for (i=0; i<n; i++)
            scanf("%I64d",&a[i]);
        for (i=0; i<n-1; i++)
            b[i] = abs(a[i]-a[i+1]);
        n--;
        for ( i = 0; i < n; ++i) t[n+i] = b[i];
        build();
        ll res = 0;

        ll temp = t[n];
        modify(0,0);
        res+=t[1];
//                cout<<'!'<<t[1]<<endl;
        modify(0,temp);

        temp = t[2*n-1];
        modify(n-1,0);
        res+=t[1];
//        cout<<'!'<<t[1]<<endl;
        modify(n-1,temp);
//        cout<<endl;
//        cout<<res<<endl;
        ll temp2 = 0;
        for (i = 0; i<n-1; i++)
        {
            temp = t[n+i];
            temp2 = t[n+i+1];
            modify(i,abs(a[i+2]-a[i]));
            modify(i+1,0);
            res+=t[1];
//            cout<<'!'<<t[1]<<endl;
            modify(i,temp);
            modify(i+1,temp2);
//            cout<<res<<endl;
        }
        printf("%I64d\n", res);
    }
    return 0;
}
/*
2
5
1 9 4 8 6
5
1 2 3 4 5
*/