#include <cstdio>
#include <algorithm>
#include <iostream>

using namespace std;
typedef long long ll;
typedef pair<int, int> PII;

int a[100005];
int b[100005];
int c[100005];

int main() {
    int n,T;
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        for (int i=1;i<=n;i++)
            scanf("%d",a+i);
        a[0]=a[1];
        a[n+1]=a[n];
        int tmp=0;
        for (int i=1;i<=n;i++){
            tmp=max(tmp,abs(a[i]-a[i-1]));
            b[i]=tmp;
        }
        tmp=0;
        for (int i=n;i>=1;i--){
            tmp=max(tmp,abs(a[i]-a[i+1]));
            c[i]=tmp;
        }
        ll ans=c[2]+b[n-1];
        for (int i=2;i<=n-1;i++){
            ans+=max(abs(a[i-1]-a[i+1]),max(b[i-1],c[i+1]));
        }
        printf("%I64d\n",ans);
    }
    return 0;
}