#include<vector>
#include<iostream>
#include<stdio.h>
#include<queue>
#include<cstring>
#include<algorithm>
using namespace std;
#define inf 0x3ffffff
#define mem(x,y) memset(x,y,sizeof(x))
#define pii pair<int,int>
#define fi first
#define se second
#define maxn 200005
#define ll long long
#define mod 1000000007
ll a[maxn];
ll p[maxn];
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        int n;
        scanf("%d",&n);
        for(int i=0;i<n;i++)
            scanf("%I64d",&a[i]);
        ll tot=0;
        for(int i=1;i<n;i++)
            p[i]=abs(a[i]-a[i-1]);
        sort(p+1,p+n);
        for(int i=0;i<n;i++)
        {
            ll may=n-1;
            if(i>0&&abs(a[i]-a[i-1])==p[may])may--;
            if(i+1<n&&abs(a[i+1]-a[i])==p[may])may--;
        
            if(i>0&&i+1<n)tot+=max(p[may],abs(a[i+1]-a[i-1]));
            else tot+=p[may];
        }
        printf("%I64d\n",tot);
    }
    return 0;
}