#include<iostream>
#include<algorithm>
#include<string.h>
#include<string>
#include<stdio.h>
#include<math.h>
#include<stack>
#include<queue>
#include<map>
#include<vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
//#define min(a,b) (a>b?b:a)
//#define max(a,b) (a>b?a:b)
#define mem(a,num) memset(a,num,sizeof(a))
#define inf(a,n) fill(a,a+n,0x3f3f3f3f)

struct M
{
    int m;
    int i,j;
    M()
    {
        m=i=j=-1;
    }
}m1,m2,m3;

int a[100005];

int main()
{
    int T,n;
    cin>>T;
    while(T--){
        scanf("%d",&n);
        int tmp;
        m1.m=m2.m=m3.m=-1;
        for(int i=0;i<n;++i){
            scanf("%d",&a[i]);
            if(i>0){
                tmp=abs(a[i]-a[i-1]);
                if(tmp>=m1.m){
                    m3=m2;
                    m2=m1;
                    m1.m=tmp;
                    m1.i=i-1;
                    m1.j=i;
                }
                else if(tmp>=m2.m){
                    m3=m2;
                    m2.m=tmp;
                    m2.i=i-1;
                    m2.j=i;
                }
                else if(tmp>=m3.m){
                    m3.m=tmp;
                    m3.i=i-1;
                    m3.j=i;
                }
            }
        }
        ll ans=0;
        if(m1.i!=0){
            ans+=m1.m;
        }
        else{
            ans+=m2.m;
        }
        for(int i=1;i<n-1;++i){
            tmp=abs(a[i-1]-a[i+1]);
            if(m1.i!=i-1&&m1.j!=i+1){
                if(m1.m<tmp)ans+=tmp;
                else ans+=m1.m;
            }
            else if(m2.i!=i-1&&m2.j!=i+1){
                if(m2.m<tmp)ans+=tmp;
                else ans+=m2.m;
            }
            else{
                if(m3.m<tmp)ans+=tmp;
                else ans+=m3.m;
            }
        }
        if(m1.j!=n-1){
            ans+=m1.m;
        }
        else{
            ans+=m2.m;
        }
        cout<<ans<<endl;
        //printf("%I64D\n",ans);
    }
    return 0;
}