#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
#define LL long long
#define ULL unsigned long long
//#define pil pair <int, LL>
#define pii pair <ULL, ULL>
//#define pii pair <int, int>
#define xx first
#define yy second
using namespace std;

const int N = 200100;

int a[N], l[N], r[N];

int main () {
//    freopen ("in.txt", "r", stdin);
    int T, n;
    cin >> T;
    while (T--) {
        scanf ("%d", &n);
        for (int i = 1; i <= n; i++) {
            scanf ("%d", &a[i]);
        }
        l[1] = r[n] = 0;
        for (int i = 2; i <= n; i++) {
            l[i] = max (l[i - 1], abs (a[i] - a[i - 1]));
        }
        for (int i = n - 1; i >= 1; i--) {
            r[i] = max (r[i + 1], abs (a[i] - a[i + 1]));
        }
        LL res = r[2] + l[n - 1];
        for (int i = 2; i < n; i++) {
            res += max (abs (a[i - 1] - a[i + 1]), max (l[i - 1], r[i + 1]));
        }
        cout << res << endl;
    }
}