/*
*Rainto96
*Beijing University of Posts and Telecommunications School of Software
Engineering
*http://blog.csdn.net/u011775691
*/
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <cstring>
#include <string>
#include <cmath>
#include <set>
#include <map>
#include <vector>
#include <climits>
#include <bitset>
using namespace std;
#define pb push_back
#define ALL(x) x.begin(),x.end()
#define PII pair<int,int>
#define MP(x,y) make_pair((x),(y))
#define ll long long
#define ull unsigned ll
#define scan(x) scanf("%d",&(x))
#define scan2(x,y) scanf("%d%d",&(x),&(y))
#define scan3(x,y,z) scanf("%d%d%d",&(x),&(y),&(z))
#define scan4(x,y,z,k) scanf("%d%d%d%d",&(x),&(y),&(z),&(k))
#define Max(a,b) a=max(a,b)
#define Min(a,b) a=min(a,b)
#define fuck(x) cout<<#x<<" "<<x<<endl
const int MX = 101111;
int a[MX], L[MX], R[MX];
int main(){
    //freopen("/home/rainto96/in.txt","r",stdin);
    int T;scanf("%d",&T);
    while(T--){
        int n;scanf("%d",&n);
        for(int i=1;i<=n;i++){
            scanf("%d",&a[i]);
        }
        a[0] = a[n+1]=0;
        L[0] = L[1] =0 ;
        for(int i=2;i<=n;i++){
            L[i] = max(L[i-1] , abs(a[i] - a[i-1]));
        }
        R[n+1] = R[n] = 0;
        for(int i=n-1;i>=1;i--){
            R[i] = max(R[i + 1], abs(a[i] - a[i+1]));
        }
        ll sum =0;
        for(int i=1;i<=n;i++){
            if(i>=2 && i<=n-1){
                int s = max(L[i-1],max(R[i+1], abs(a[i+1] - a[i-1])));
                sum +=s;
            }else if(i == 1){
                sum += R[2];
            }else{
                sum += L[n-1];
            }
        }
        cout<<sum<<endl;
    }
    return 0;
}