HDU 5805 NanoApe Loves Sequence

时间：2021-05-13 15:09:19

处理出每个位置左边的最大值和右边的最大值。然后就可以o(1)计算去掉某位置的最大值了。

#pragma comment(linker, "/STACK:1024000000,1024000000")

#include<cstdio>

#include<cstring>

#include<cmath>

#include<algorithm>

#include<vector>

#include<map>

#include<set>

#include<queue>

#include<stack>

#include<iostream>

using namespace std;

typedef long long LL;

const double pi=acos(-1.0),eps=1e-;

void File()

{

    freopen("D:\\in.txt","r",stdin);

    freopen("D:\\out.txt","w",stdout);

}

inline int read()

{

    char c = getchar();  while(!isdigit(c)) c = getchar();

    int x = ;

    while(isdigit(c)) { x = x *  + c - ''; c = getchar(); }

    return x;

}

const int maxn=+;

int T,n,a[maxn],L[maxn],R[maxn];

LL ans;

int main()

{

    scanf("%d",&T);

    while(T--)

    {

        ans=; memset(L,,sizeof L); memset(R,,sizeof R);

        scanf("%d",&n); for(int i=;i<=n;i++) scanf("%d",&a[i]);

        for(int i=;i<=n;i++) L[i]=max(L[i-],abs(a[i]-a[i-]));

        for(int i=n-;i>=;i--) R[i]=max(R[i+],abs(a[i]-a[i+]));

        for(int i=;i<=n;i++)

        {

            if(i==) ans=ans+R[];

            else if(i==n) ans=ans+L[n-];

            else ans=ans+max(L[i-],max(R[i+],abs(a[i-]-a[i+])));

        }

        printf("%lld\n",ans);

    }

    return ;

}

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