/*第二次来水BC，暑假最后一场了，这次收获不错，水出两题，虽然第二题不知道什么是线段树，但是还是按照自己想法搞出来了，加油*/
#include <iostream>
#include <stdio.h>
#include <cmath>
#include <vector>
#include <algorithm>
#include <string.h>
#define N 100010
#define M 100000
using namespace std;
long long  n, dp[N],pd[N],a[N], tep;
long long Max(long long a,long long b,long long c)
{
    long long d=max(a,b);
    long long e=max(b,c);
    return max(d,e);
}
int main()
{
    //freopen("in.txt","r",stdin);
    int t;
    scanf("%d",&t);
    while(t--)
    {
        memset(dp,0,sizeof(dp));
        memset(pd,0,sizeof(pd));
        vector <long long > v;
        v.clear();
        v.push_back(0);
        scanf("%lld",&n);
        for(int i = 1; i <= n; i++)
        {
            
            scanf("%lld",&tep);
            v.push_back(tep);
        }
        v.push_back(0);
        dp[1]=0;
        for(int i = 2; i <= n;i++)
            if(abs(v[i] - v[i - 1])>dp[i-1])
            {
                dp[i]=abs(v[i] - v[i-1]);
            }
            else
                dp[i] = dp[i - 1];
            
        reverse(v.begin(), v.end());
        pd[1]=0;
        for(int i = 2; i <= n; i++)
            if(abs(v[i] - v[i-1]) > pd[i-1])
                pd[i] = abs(v[i] - v[i-1]);
            else
                pd[i] = pd[i - 1];
        reverse(v.begin(), v.end());
        long long s = 0;
        for(int i=1;i<=n;i++)
        {
            if(i==1)
                s+=pd[n-1];
            else if(i==n)
                s+=dp[n-1];
            else
                s+=Max(dp[i-1],abs(v[i+1] - v[i-1]),pd[n-i]);
        }
        printf("%lld\n",s);
    }
    return 0;
}