#include <stdio.h>
#include <iostream>
#include <math.h>
#include <algorithm>
using namespace std;
const int N = 1e5 + 5;
int n, a[N];

int main() {
    int t; scanf("%d", &t);
    while (t--) {
        long long S = 0;
        scanf("%d", &n);
        for (int i = 1; i <= n; i++) scanf("%d", a + i);
        int ma1 = 0, ma2 = 0, ma3 = 0;
        for (int i = 1; i < n; i++) {
            if (abs(a[i] - a[i+1]) > ma1) {
                ma3 = ma2;
                ma2 = ma1;
                ma1 = abs(a[i] - a[i+1]);
            } else
            if (abs(a[i] - a[i+1]) > ma2) {
                ma3 = ma2;
                ma2 = abs(a[i] - a[i+1]);
            } else
            if (abs(a[i] - a[i+1]) > ma3) ma3 = abs(a[i] - a[i+1]);
        }
        for (int i = 1; i <= n; i++) {
            if (i == 1) {
                int tmp = abs(a[1] - a[2]);
                if (tmp == ma1) S += ma2;
                else S += ma1;
            } else
            if (i == n) {
                int tmp = abs(a[n] - a[n-1]);
                if (tmp == ma1) S += ma2;
                else S += ma1;
            } else {
                int t1 = abs(a[i] - a[i-1]);
                int t2 = abs(a[i] - a[i+1]);
                int t3 = abs(a[i+1] - a[i-1]);
                if (t3 >= ma1) S += t3;
                else {
                    if (t1 < t2) swap(t1, t2);
                    if (t1 != ma1) S += ma1;
                    else if (t2 != ma2) S += ma2;
                    else S += ma3;
                }
            }
        }
        printf("%I64d\n", S);
    }
}