#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <functional>

using namespace std;

#define REP(i,n)        for(int i(0); i <  (n); ++i)
#define rep(i,a,b)        for(int i(a); i <= (b); ++i)
#define dec(i,a,b)        for(int i(a); i >= (b); --i)
#define for_edge(i,x)        for(int i = H[x]; i; i = X[i])

#define LL    long long
#define ULL    unsigned long long
#define MP    make_pair
#define PB    push_back
#define FI    first
#define SE    second
#define INF    1 << 30

const int N    =    100000        +    10;
const int M    =    10000        +    10;
const int Q    =    1000        +    10;
const int A    =    30        +    1;


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

int main(){
#ifndef ONLINE_JUDGE
    freopen("test.txt", "r", stdin);
    freopen("test.out", "w", stdout);
#endif


    scanf("%d", &T);
    REP(Case, T){
        memset(l, 0, sizeof l);
        memset(r, 0, sizeof r);
        memset(a, 0, sizeof a);
        scanf("%d", &n);
        rep(i, 1, n) scanf("%d", a + i);
        l[2] = abs(a[2] - a[1]);
        rep(i, 3, n) l[i] = max(abs(a[i] - a[i - 1]), l[i - 1]);
        r[n - 1] = abs(a[n] - a[n - 1]);
        dec(i, n - 2, 1) r[i] = max(abs(a[i] - a[i + 1]), r[i + 1]);
        /*rep(i, 2, n) printf("%d ", l[i]); puts("");
        rep(i, 1, n - 1) printf("%d ", r[i]); puts("");*/
        LL ans = r[2] + l[n - 1];
        rep(i, 2, n - 1) ans += max(max(l[i - 1], r[i + 1]), abs(a[i + 1] - a[i - 1]));
        printf("%I64d\n", ans);
    }
    
    return 0;
    
}