#include <cstdio>

#include <cmath>

#include <cstring>

#include <iostream>

#include <algorithm>

#include <queue>

#include <vector>

#include <map>



using namespace std;



typedef long long LL;


int T;
LL a[100005],f[100005],pref[100005],suff[100005];
LL ans,dq;
int n;

int main()

{
    scanf("%d",&T);
    while (T--)
    {
        scanf("%d",&n);
        for (int i=1;i<=n;++i) scanf("%I64d",&a[i]);
        for (int i=2;i<=n;++i) f[i]=abs(a[i]-a[i-1]);
        pref[2]=f[2];
        for (int i=3;i<=n;++i) pref[i]=max(pref[i-1],f[i]);
        suff[n]=f[n];
        for (int i=n-1;i>=2;--i) suff[i]=max(suff[i+1],f[i]);
        ans=suff[3];//del 1
        suff[n+1]=0;
        for (int i=2;i<n;++i)
        {    
            dq=a[i+1]-a[i-1];
            dq=abs(dq);
            dq=max(dq,pref[i-1]);
            dq=max(dq,suff[i+2]);
            ans+=dq;
        }
        ans+=pref[n-1];//del n
        printf("%I64d\n",ans);
    }

    return 0;

}