#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long LL;
LL n,ans;
LL a[100010],maxf[100010],maxb[100010];
LL mabs(LL x)
{
    if(x<0) return -x;
    return x;
}
void init()
{
    ans=0;
    memset(maxf,0,sizeof(maxf));
    memset(maxb,0,sizeof(maxb));
    scanf("%I64d",&n);
    for(int i=1;i<=n;i++)
        scanf("%I64d",&a[i]);
    for(int i=2;i<=n;i++)
        maxf[i]=max(mabs(a[i]-a[i-1]),maxf[i-1]);
    for(int i=n-1;i>=1;i--)
        maxb[i]=max(mabs(a[i]-a[i+1]),maxb[i+1]);
}
void work()
{
    ans+=maxb[2]+maxf[n-1];
    for(int i=2;i<n;i++)
        ans+=max(mabs(a[i-1]-a[i+1]),max(maxf[i-1],maxb[i+1]));
    printf("%I64d\n",ans);
}
int main()
{
    int t;
    cin >> t;
    while(t--)
    {
        init();
        work();
    }
    return 0;
}