#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
typedef long long ll;
ll m[100005];
ll Abs(ll a) { return (a >= 0) ? a : -1 * a; }


int main()
{
    int T;
    scanf("%d", &T);
    while(T--) {
        ll n, a = 0, p;
        scanf("%I64d", &n);
        for(int i = 1; i <= n; ++i) {
            scanf("%I64d", &m[i]);
        }
        for(int i = 2; i <= n; ++i) {
            if(a < Abs(m[i] - m[i - 1])) {
                p = i;
                a = Abs(m[i] - m[i - 1]);
            }
        }
        ll ans = 0, aa = 0;
        for(int i = 1; i <= n; ++i) {
            if(i == p || i == p - 1) {
                aa = 0;
                for(int j = 1; j <= n; ++j) {
                    if(j == i) {
                        if(j - 1 >= 1 && j + 1 <= n) {
                            aa = max(aa, Abs(m[j + 1] - m[j - 1]));
                        }
                    }
                    if(j != i && j - 1 != i && j - 1 >= 1) aa = max(aa, Abs(m[j] - m[j - 1]));
                }
            } else {
                aa = a;
                if(i + 1 <= n && i - 1 >= 1) aa = max(a, Abs(m[i + 1] - m[i - 1]));
            }
            ans += aa;
        }
        printf("%I64d\n", ans);
    }
    return 0;
}