#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cstring>
#include <string>
#include <cmath>
#include <algorithm>
#include <map>
#include <vector>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;

const int MaxN = 1e5;
int a[MaxN + 5], n, T;
struct Point{
    int ans, l, r;
}seq[MaxN + 5];

bool cmp(Point x, Point y) {return x.ans > y.ans;}

int main()
{
    scanf("%d", &T);
    while(T--)
    {
        scanf("%d", &n);
        for(int i = 1; i <= n; i++) scanf("%d", &a[i]);
        for(int i = 2; i <= n; i++)
        {
            seq[i - 1].ans = abs(a[i] - a[i - 1]);
            seq[i - 1].l = i - 1;
            seq[i - 1].r = i;
        }
        seq[n].ans = 0;
        seq[n].l = 0;
        seq[n].r = 0;
        sort(seq + 1, seq + n, cmp);
        LL ans = 0;
        int p = 1;
        while(seq[p].l == 1 || seq[p].r == 1) p++;
        ans += seq[p].ans;
        for(int i = 2; i <= n - 1; i++)
        {
            p = 1; int t = abs(a[i + 1] - a[i - 1]);
            while(seq[p].l == i || seq[p].r == i) p++;
            ans += max(t, seq[p].ans);
        }
        p = 1;
        while(seq[p].l == n || seq[p].r == n) p++;
        ans += seq[p].ans;
        printf("%I64d\n", ans);
    }
}