#include<stdio.h>
#include<cmath>
#include<iostream>
#include<cstring>
#include<algorithm>
#include<string>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<utility>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
const int MN = 100000 + 10;
const int ME = 1000000 + 10;
const LL mod = 998244353LL;
const double pi = acos(-1.0);
const int Intmax = (~(1 << 31));
const int Intmin = (1 << 31);
const LL LLmax = (~(1LL << 63));
const LL LLmin = (1LL << 63);
const ULL ULLmax = (~(0ULL));

int a[MN];
int main() {
#ifndef ONLINE_JUDGE
    freopen("1.cpp", "r", stdin);
#endif // ONLINE_JUDGE
    int t;
    scanf("%d",&t);
    while(t--){
        int n;
        int i;
        scanf("%d",&n);
        for(i=0;i<n;i++) scanf("%d",&a[i]);
        int Max=-1;
        int p,q;
        for(i=0;i<n-1;i++){
            int pans=abs(a[i]-a[i+1]);
            if(pans>Max){
                Max=pans;
                p=i;
                q=i+1;
            }
        }
        LL ans=0;
        for(i=0;i<n;i++){
            if(i==p||i==q){
                int j;
                if(i==p){
                    int pans=0;
                    for(j=0;j<n-1;j++){
                        if(j==p) continue;
                        else if(j+1==p){
                            pans=max(pans,abs(a[j]-a[q]));
                        }else{
                            pans=max(pans,abs(a[j]-a[j+1]));
                        }
                    }
                    ans+=pans;
                }else{
                    int pans=0;
                    for(j=0;j<n-1;j++){
                        if(j==q) continue;
                        else if(j+1==q){
                            if(q+1<n) pans=max(pans,abs(a[j]-a[q+1]));
                        }else{
                            pans=max(pans,abs(a[j]-a[j+1]));
                        }
                    }
                    ans+=pans;
                }
            }else{
                if(i-1>=0&&i+1<n){
                    ans+=max(Max,abs(a[i-1]-a[i+1]));
                }
                else ans+=Max;
            }
        }
        printf("%I64d\n",ans);
    }
    return 0;
}