//#include <bits\stdc++.h>
//#pragma comment(linker, "/STACK:102400000,102400000")
#include <cstdio>
#include <cstring>
#include <iostream>
#include <cstdlib>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <ctime>
#include <cmath>
#include <algorithm>
#include <bitset>

#define sqr(x) (x)*(x)
#define lson (p<<1)
#define rson (lson | 1)
#define eps 1e-10
#define pii pair<int,int>
#define mk(x,y) make_pair(x,y)

using namespace std;
typedef long long llg;
const int N = 1e5+10;
int a[N],l[N],r[N];
int main()
{
    int cas,n;
    scanf("%d",&cas);
    while(cas--)
    {
        scanf("%d",&n);
        for(int i=1;i<=n;i++) scanf("%d",&a[i]);
        memset(l,0,sizeof(l));
        memset(r,0,sizeof(r));
        for(int i=n-1;i;i--)
        {
            r[i] = max(abs(a[i+1]-a[i]),r[i+1]);
        }
        llg ans = r[2];
        a[0] = a[2];
        a[n+1] = a[n-1];
        for(int i=2;i<=n;i++)
        {
            l[i] = max(abs(a[i]-a[i-1]),l[i-1]);
            ans += max(abs(a[i+1]-a[i-1]),max(r[i+1],l[i-1]) );
        }
        cout<<ans<<endl;
    }
    return 0;
}