#include <iostream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#define LL long long
#define maxn 100005

using namespace std;

int n,a[maxn],b[maxn],T;

int main()
{
    scanf("%d",&T);
    while (T--)
    {
        memset(a,0,sizeof(a));
        scanf("%d",&n);
        for (int i=0;i<n;i++) scanf("%d",&a[i]);
        int Max=0,p=0;
        for (int i=0;i<n-1;i++)
        {
            b[i]=abs(a[i+1]-a[i]);
            if (Max<b[i])
            {
                p=i;
                Max=b[i];
            }
        }
        LL ans=0;
        if (p==0)
        {
            ans=Max;
            for (int i=p+2;i<n-1;i++)  ans+=(LL)max(Max,abs(a[i+1]-a[i-1]));
            Max=0;
            for (int i=p+2;i<n-1;i++) Max=(LL)max(Max,b[i]);
            ans+=(LL)max(Max,abs(a[p+2]-a[p+1]) );
            ans+=(LL)max(Max,abs(a[p+2]-a[p]));
            printf("%I64d\n",ans);
            continue ;
        }
        if (p==n-2)
        {
            ans=Max;
            for (int i=1;i<n-2;i++) ans+=(LL)max(Max,abs(a[i+1]-a[i-1]));
            Max=0;
            for (int i=0;i<n-3;i++) Max=max(Max,b[i]);
            ans+=(LL)max(Max,abs(a[n-1]-a[n-3]));
            ans+=(LL)max(Max,abs(a[n-2]-a[n-3]) );
            printf("%I64d\n",ans);
            continue ;
        }
        ans=2*Max;
        for (int i=1;i<p;i++) ans+=(LL)max(Max,abs(a[i+1]-a[i-1]));
        for (int i=p+2;i<n-1;i++)  ans+=(LL)max(Max,abs(a[i+1]-a[i-1]));
        Max=0;
        for (int i=0;i<p-1;i++) Max=max(Max,b[i]);
        for (int i=p+2;i<n-1;i++) Max=max(Max,b[i]);

        ans+=(LL)max(abs(a[p+1]-a[p-1]),max(Max,b[p+1]));
        ans+=(LL)max(abs(a[p+2]-a[p]),max(Max,b[p-1]));

        printf("%I64d\n",ans);
    }
    return 0;
}