#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<map>
#include<queue>
#include<vector>
#define NN 1050
#define MM 50011
#define INF 0x7ffffff
#define For(i,n) for(int i=1;i<=n;i++)
using namespace std;
#define maxn 105000
#define MAXM 50000+10
#define LL long long
int N,M,T;
LL A[maxn],B[maxn];
LL C[maxn],D[maxn],E[maxn];
LL vis[maxn];

bool cp(LL a,LL b)
{
    return a>b;
}

int main()
{
    cin>>T;
    while(T--)
    {
        memset(vis,0,sizeof(vis));
        scanf("%d",&N);
        priority_queue<LL >Q;
        
        For(i,N)
        {
            scanf("%lld",&A[i]);
        }
        LL G=0;
        if(N==3)
        {
            G+=abs(A[3]-A[2]);
            G+=abs(A[3]-A[1]);
            G+=abs(A[2]-A[1]);
            cout<<G<<endl;
            continue;
        }
        LL MAXN=0;
        int t;
        for(int i=2;i<=N;i++)
        {
            C[i]=abs(A[i]-A[i-1]);
            Q.push(C[i]);
        
            if(MAXN<C[i])
            {
                MAXN=C[i];
                t=i;
            }
        }
        int sum=0;
        for(int i=1;i<=N;i++)
        {
            if(C[i]==MAXN)
            {
                sum++;
                vis[i]=1;
            }
        }
        int s=sum;
        memcpy(D,C,sizeof(C));
        sort(D+1,D+N,cp);
        LL MAXX=MAXN;
        for(int i=1;i<=N;i++)
        {
            if(D[i]<MAXX)
            {
                MAXX=D[i];
                break;
            }
        }
        
        LL m=0;
        for(int i=3;i<=N;i++) 
            m=max(m,abs(A[i]-A[i-1]));
        G+=m;
        m=0;    
        for(int i=2;i<N;i++)
            m=max(m,abs(A[i-1]-A[i]));
        G+=m;
        
        
        
        for(int i=2;i<=N-1;i++)
        {
            s=sum;
            m=abs(A[i+1]-A[i-1]);
            if(m>=MAXN)
            {
                G+=m;
                continue;
            }
            
            LL p=C[i];
            LL q=C[i+1];
            int u=0;
            if(Q.top()==p)
            {
                E[++u]=Q.top();
                Q.pop();
            }
            if(Q.top()==q && Q.top()==MAXN)
            {
                E[++u]=Q.top();
                Q.pop();
            }
            G+=Q.top();
            
            if(u==2)
            {
                Q.push(MAXN);
                Q.push(MAXN);
            }
            
            if(u==1)
            {
                Q.push(MAXN);
            }
            
        }
        
        printf("%lld\n",G);
    }
    
    
    return 0;
} 

/*

5
5 
1 7 1 8 5 



*/