#include <cstdio>

int n,t;
int data[100010],left[100010],right[100010];

inline int maximum(int a,int b)
{
    return a > b ? a : b;
}

inline int abs(int x)
{
    return x > 0 ? x : -x;
}

int main(void)
{
    int i,j,k;
    long long answer;

    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        for(i = 1;i <= n;++i)
            scanf("%d",&data[i]);

        left[1] = right[n] = 0;
        for(i = 2;i <= n;++i)
            left[i] = maximum(left[i - 1],abs(data[i] - data[i - 1]));
        for(i = n - 1;i >= 1;--i)
            right[i] = maximum(right[i + 1],abs(data[i + 1] - data[i]));

        answer = left[n - 1] + right[2];
        for(i = 2;i <= n - 1;++i)
            answer += maximum(maximum(left[i - 1],right[i + 1]),abs(data[i + 1] - data[i - 1]));

        printf("%I64d\n",answer);
    }
}