#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;

#define getmid(l,r) ((l) + ((r) - (l)) / 2)
#define MEM(a,b) memset(a,b,sizeof(a))
#define MP(a,b) make_pair(a,b)
#define PB push_back

typedef long long ll;
typedef pair<int,int> pii;
const double eps = 1e-8;
const int INF = (1 << 30) - 1;
const int maxn = 200010;
const int mod = 998244353;

int T,n;
int A[maxn],pre[maxn],suf[maxn];

int main(){
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        for(int i = 1; i <= n; ++i) scanf("%d",&A[i]);
        memset(pre,0,sizeof(pre));
        memset(suf,0,sizeof(suf));
        for(int i = 2; i <= n; ++i){
            pre[i] = abs(A[i] - A[i - 1]);
            pre[i] = max(pre[i],pre[i - 1]);
        }
        for(int i = n - 1; i >= 1; --i){
            suf[i] = abs(A[i] - A[i + 1]);
            suf[i] = max(suf[i],suf[i + 1]);
        }
        ll ans = 0;
        for(int i = 1; i <= n; ++i){
            if(i == 1) ans += suf[2];
            else if(i == n) ans += pre[n - 1];
            else{
                ans += max(pre[i - 1],max(suf[i + 1],abs(A[i + 1] - A[i - 1])));
                //printf("%d %d\n",i,max(pre[i - 1],max(suf[i + 1],abs(A[i + 1] - A[i - 1]))));
            }
        }
        printf("%I64d\n",ans);
    }
    return 0;
}