#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<set>
#include<vector>
#include<queue>
#include<algorithm>
#define maxn 100007
#define infm ((1<<30)-1)
#define fst first
#define scn second

using namespace std;


typedef pair<double,double> PAf;
typedef pair<int,int> PA;
typedef long long LL;
typedef pair<int,PA> TA;

int n,m,ans,tot;
const int p=1000000007;

LL qpow(LL a,LL b)
{
    LL ans;
    for(ans=1;b;b>>=1,a=a*a%p)
        if(b&1)ans=ans*a%p;
    return ans;
}
LL getc(LL n,LL m)
{
    if(n<m)return 0;
    if(m>n-m)m=n-m;
    LL s1=1,s2=1;
    for(LL i=0;i<m;i++)
    {
        s1=s1*(n-i)%p;
        s2=s2*(i+1)%p;
    }
    return s1*qpow(s2,p-2)%p;
}

LL fact[maxn];

void extgcd(LL a, LL b, LL &x, LL &y)
{
    if (b != 0) {
        extgcd(b, a % b, y, x);
        y -= (a / b) * x;
    }
    else {
        x = 1;
        y = 0;
    }
}
const int modp=p;
LL mod_inv(LL a)
{
    LL x, y;
    extgcd(a, modp, x, y);
    return (modp + x % modp) % modp;
}

LL mod_fact(LL n, LL p, LL& e) {
    e=0;
    if (n==0) return 1;
    LL res=mod_fact(n/p,p,e);
    e+=n/p;
    if (n/p%2!=0) return res*(p-fact[n%p])%p;
    return res*fact[n%p]%p;
}

LL lucas(LL n,LL k)
{
    if (n<0||k<0||n<k) return 0;
    LL e1,e2,e3;
    LL a1=mod_fact(n,p,e1), a2=mod_fact(k,p,e2), a3=mod_fact(n-k,p,e3);
    if (e1>e2+e3) return 0;
    return a1*mod_inv(a2*a3%p)%p;

}

int q[maxn];
int a[4];

int main()
{
    int T=1;
    scanf("%d",&T);
    for (int cT=1;cT<=T;++cT)
    {
        tot=0;
        scanf("%d",&n);
        for (int i=0;i<n;++i) scanf("%d",q+i);
        memset(a,-1,sizeof(a));
        for (int i=1;i<n;++i) {
            int x=abs(q[i]-q[i-1]);
            for (int j=0;j<4;++j) {
                if (x>a[j]) {
                    for (int k=j+1;k<4;++k) a[k]=a[k-1];
                    a[j]=x;
                    break;
                }
            }
        }
        LL ans=0;
        for (int i=0;i<n;++i) {
            if (i==0) {
                int x=abs(q[i+1]-q[i]);
                if (x==a[0]) ans+=a[1];
                else ans+=a[0];
            }
            else if (i==n-1) {
                int x=abs(q[i]-q[i-1]);
                if (x==a[0]) ans+=a[1];
                else ans+=a[0];
            }
            else {
                int x=abs(q[i]-q[i-1]);
                int y=abs(q[i]-q[i+1]);
                int cnt=0;
                if (x<y) swap(x,y);
                if (x==a[0]) {
                    ++cnt;
                    if (y==a[1]) ++cnt;
                }
                ans+=max(a[cnt],abs(q[i-1]-q[i+1]));
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}