#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <iostream>
#include <cmath>
using namespace std;
const int maxn = 111111;

long long a[maxn], dp1[maxn], dp2[maxn];

int main() {
    int T;
    scanf("%d", &T);
    while(T--) {
        int n;
        scanf("%d", &n);
        for(int i = 1; i <= n; i++){
            scanf("%I64d", &a[i]);
            dp1[i] = dp2[i] = 0;
        }
        for(int i = 2; i <= n; i++)
            dp1[i] = max(dp1[i-1], abs(a[i]-a[i-1]));
        for(int i = n-1; i >= 1; i--)
            dp2[i] = max(dp2[i+1], abs(a[i]-a[i+1]));
        long long ans = dp2[2] + dp1[n-1];
        for(int i = 2; i <= n-1; i++)
            ans += max(abs(a[i+1]-a[i-1]) , max(dp1[i-1], dp2[i+1]));
        printf("%I64d\n",ans);
    }
    return 0;
}