题意

给定一个数列，随机从该数列里删除一个数，求该数列的的相邻之间的绝对值的最大值的和。

思路

两个数列来分别维护i位前面的相邻的绝对值的最大以及i后面的最大，枚举每一个可能删除的数，然后分别从左右和要删除的这个空档里娶一个最大的值。

code：

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <sstream>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>using namespace std;typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;const int INF=0x3fffffff;
const int inf=-INF;
const int N=100005;
const int M=2005;
const int mod=1000000007;
const double pi=acos(-1.0);#define cls(x,c) memset(x,c,sizeof(x))
#define cpy(x,a) memcpy(x,a,sizeof(a))
#define ft(i,s,n) for (int i=s;i<=n;i++)
#define frt(i,s,n) for (int i=s;i>=n;i--)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define lrt  rt<<1
#define rrt  rt<<1|1
#define middle int m=(r+l)>>1
#define lowbit(x) (x&-x)
#define pii pair<int,int>
#define mk make_pair
#define IN freopen("in.txt","r",stdin)
#define OUT freopen("out.txt","w",stdout)int read() {char ch;while (ch = getchar(), !isdigit(ch));int res = ch - '0';while (ch = getchar(), isdigit(ch))res = res * 10 + ch - '0';return res;
}
//++++++++++++密++++++++++++++封++++++++++++++++++++线ll v[N],s1[N],s2[N];
int main()
{int T=read();ft(ca,1,T){int n=read();memset(s1,0,sizeof(s1));memset(s2,0,sizeof(s2));ft(i,1,n){scanf("%I64d",v+i);if (i>1){ll tq=abs(v[i]-v[i-1]);s1[i]=max(s1[i-1],tq);}}frt(i,n,1){if (i<n){ll tq=abs(v[i]-v[i+1]);s2[i]=max(s2[i+1],tq);}}ll ans=s2[2]+s1[n-1];ft(i,2,n-1){ll tq=abs(v[i+1]-v[i-1]);tq=max(tq,s1[i-1]);tq=max(tq,s2[i+1]);ans+=tq;}printf("%I64d\n",ans);}
}