#include <cstdio>

#include <cstring>

#include <cmath>

#include <algorithm>

using namespace std;

typedef long long LL;

const int N = 1e5+;

int a[N],T,n,b[N],l[N],r[N];

int main(){

  scanf("%d",&T);

  while(T--){

   scanf("%d",&n);

   for(int i=;i<=n;++i)scanf("%d",&a[i]);

   LL ret=;

   for(int i=;i<n;++i){

      b[i]=abs(a[i]-a[i+]);

      l[i]=max(l[i-],b[i]);

   }

   r[n]=;

   for(int i=n-;i>;--i)r[i]=max(r[i+],b[i]);

   for(int i=;i<=n;++i){

     if(i==)ret+=r[];

     else if(i==n)ret+=l[n-];

     else{

       int tmp=max(l[i-],r[i+]);

       tmp=max(tmp,abs(a[i+]-a[i-]));

       ret+=tmp;

     }

   }

   printf("%I64d\n",ret);

  }

  return ;

}