#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#define mp(a,b) make_pair(a,b)
using namespace std;
typedef long long LL;
typedef double db;
const int maxn=100005;
int a[maxn];
int x[maxn];
int y[maxn];
int main()
{
    int t,n;
    cin>>t;
    while (t--) {
        scanf("%d",&n);
        for(int i=1;i<=n;i++){
            scanf("%d",&a[i]);
        }
        long long s=0;
        x[1]=0;
        for(int i=2;i<=n;i++){
            x[i]=max(x[i-1],abs(a[i]-a[i-1]));
        }
        y[n]=0;
        for(int i=n-1;i>=1;i--){
            y[i]=max(y[i+1],abs(a[i+1]-a[i]));
        }
        s+=y[2];
        s+=x[n-1];
        for(int i=2;i<=n-1;i++){
            int w=abs(a[i+1]-a[i-1]);
            if(w<=x[i-1]||w<=y[i+1]) s+=max(x[i-1],y[i+1]);
            else{
                s+=w;
            }
        }
        printf("%I64d\n",s);
    }
}