spoj 4487. Can you answer these queries VI (gss6) splay 常数优化

4487. Can you answer these queries VI

Problem code: GSS6



 

Given a sequence A of N (N <= 100000) integers, you have to apply Q (Q <= 100000) operations:

Insert, delete, replace an element, find the maximum contiguous(non empty) sum in a given interval.

Input

The first line of the input contains an integer N.
The following line contains N integers, representing the starting
sequence A1..AN, (|Ai| <= 10000).

The third line contains an integer Q. The next Q lines contains the operations in following form:

I x y: insert element y at position x (between x - 1 and x).
D x  : delete the element at position x.
R x y: replace element at position x with y.
Q x y: print max{Ai + Ai+1 + .. + Aj | x <= i <= j <= y}.

All given positions are valid, and given values are between -10000 and +10000.

The sequence will never be empty.

Output

For each "Q" operation, print an integer(one per line) as described above.

Example

Input:
5
3 -4 3 -1 6
10
I 6 2
Q 3 5
R 5 -4
Q 3 5
D 2
Q 1 5
I 2 -10
Q 1 6
R 2 -1
Q 1 6

Output:
8
3
6
3
5


  第二次写splay居然遇上了考splay的常数优化。弄了很久。首先是读入优化,貌似SPOJ上面数据有' '所以要特殊判断。然后inline所有函数,最后把splay移到一个struct里面会加速很多。

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<cmath>
#include<algorithm>
#include<set>
#include<map>
#include<vector>
#include<string>
#include<queue>
using namespace std;
#ifdef WIN32
#define LL "%I64d"
#else
#define LL "%lld"
#endif
#define MAXN 110000
#define MAXV MAXN*2
#define MAXE MAXV*2
#define MAXT MAXN*2
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
#define lch splay[now].ch[0]
#define rch splay[now].ch[1]
typedef long long qword;
inline int nextInt()
{
        char ch;
        int x=0;
        bool flag=false;
        do
                ch=(char)getchar(),flag=(ch=='-')?true:flag;
        while(ch<'0'||ch>'9');
        do x=x*10+ch-'0';
        while (ch=(char)getchar(),ch<='9' && ch>='0');
        return x*(flag?-1:1);
}

int n,m;
int root=0,topt=0;;
struct sss
{
        int lx,rx,mx,val,sum,siz,pnt;
        int ch[2];
}splay[MAXT];
inline void up(int now)
{
        splay[now].lx=splay[now].rx=splay[now].mx=-INF;
        if (lch)splay[now].lx=max(splay[now].lx,splay[lch].lx);
        splay[now].lx=max(splay[now].lx,max(splay[lch].sum+splay[now].val,splay[lch].sum+splay[now].val+splay[rch].lx));
        
        if (rch)splay[now].rx=max(splay[now].rx,splay[rch].rx);
        splay[now].rx=max(splay[now].rx,max(splay[rch].sum+splay[now].val,splay[rch].sum+splay[now].val+splay[lch].rx));

        splay[now].mx=splay[now].val;
        if (lch)splay[now].mx=max(splay[now].mx,splay[lch].mx);
        if (rch)splay[now].mx=max(splay[now].mx,splay[rch].mx);
        splay[now].mx=max(splay[now].mx,splay[lch].rx+splay[rch].lx+splay[now].val);
        splay[now].mx=max(splay[now].mx,splay[rch].lx+splay[now].val);
        splay[now].mx=max(splay[now].mx,splay[lch].rx+splay[now].val);

        splay[now].siz=splay[lch].siz+splay[rch].siz+1;
        splay[now].sum=splay[lch].sum+splay[rch].sum+splay[now].val;
}

inline void Rotate(int now)
{
        int p=splay[now].pnt,anc=splay[p].pnt;
        int dir=splay[p].ch[0]==now;
        if (anc)
                splay[anc].ch[splay[anc].ch[1]==p]=now;
        splay[now].pnt=anc;

        splay[splay[now].ch[dir]].pnt=p;
        splay[p].ch[1-dir]=splay[now].ch[dir];

        splay[p].pnt=now;
        splay[now].ch[dir]=p;
        up(p);
        up(now);
}
/*
inline int Get_kth(int now,int rk)
{
        if (rk==siz[splay[now].ch[0]]+1)
                return now;
        if (rk<siz[splay[now].ch[0]]+1)
                return Get_kth(splay[now].ch[0],rk);
        else 
                return Get_kth(splay[now].ch[1],rk-siz[splay[now].ch[0]]-1);
}*/
inline int Get_kth(int rk)
{
        int now=root;
        while (rk!=splay[splay[now].ch[0]].siz+1)
        {
                if (rk>splay[splay[now].ch[0]].siz+1)
                {
                        rk-=splay[splay[now].ch[0]].siz+1;
                        now=splay[now].ch[1];
                }else 
                {
                        now=splay[now].ch[0];
                }
        }
        return now;
}

inline void Splay(int now,int tp=0)
{
        if (now==tp)return ;
        while (splay[now].pnt!=tp)
        {
                int p=splay[now].pnt,anc=splay[p].pnt;
                if (anc==tp)
                        Rotate(now);
                else if( (splay[anc].ch[0]==p) == (splay[p].ch[0]==now))
                {
                        Rotate(p);
                        Rotate(now);
                }else
                {
                        Rotate(now);
                        Rotate(now);
                }
        }
        if (tp==0)root=now;
}
inline void Insert(int pos,int v)
{
        int now=++topt;
        splay[now].ch[0]=splay[now].ch[1]=0;
        splay[now].pnt=0;
        splay[now].val=v;
        splay[now].siz=1;
        splay[now].lx=splay[now].rx=splay[now].mx=splay[now].sum=v;
        if (!pos)
        {
                Splay(Get_kth(1));
                splay[now].ch[1]=root;
                splay[root].pnt=now;
                root=now;
                up(now);
                return ;
        }
        Splay(Get_kth(pos));
        splay[now].pnt=root;
        splay[now].ch[1]=splay[root].ch[1];
        splay[splay[root].ch[1]].pnt=now;
        splay[root].ch[1]=now;
        up(now);
        up(root);
        return ;
}
inline void Delete(int pos)
{
        Splay(Get_kth(pos));
        if (pos!=splay[root].siz)
        {
                Splay(Get_kth(pos+1),root);/**/
                splay[splay[root].ch[1]].ch[0]=splay[root].ch[0];
                splay[splay[root].ch[0]].pnt=splay[root].ch[1];;
                splay[splay[root].ch[1]].pnt=splay[root].pnt;
                root=splay[root].ch[1];
        }else
        {
                root=splay[root].ch[0];
                splay[root].pnt=0;
        }
        up(root);
}
inline int Qry_mxs(int l,int r)
{
        if (l==1 && r==splay[root].siz)
        {
                return splay[root].mx;
        }else if (l==1)
        {
                Splay(Get_kth(r+1));
                return splay[splay[root].ch[0]].mx;
        }else if (r==splay[root].siz)
        {
                Splay(Get_kth(l-1));
                return splay[splay[root].ch[1]].mx;
        }else
        {
                Splay(Get_kth(l-1));
                Splay(Get_kth(r+1),root);
                return splay[splay[splay[root].ch[1]].ch[0]].mx;
        }
}
inline void Chg_val(int pos,int v)
{
        Splay(Get_kth(pos));
        splay[root].val=v;
        up(root);
}
void Scan(int now)
{
        if (!now)return ;
        if (splay[now].siz!=splay[lch].siz+splay[rch].siz+1)throw 2;
        if (splay[now].ch[0])
        {
                if (splay[splay[now].ch[0]].pnt!=now)throw 1;
                Scan(splay[now].ch[0]);
        }
        printf("%d ",splay[now].val);
        if (splay[now].ch[1])
        {
                if (splay[splay[now].ch[1]].pnt!=now)throw 1;
                Scan(splay[now].ch[1]);
        }
}
void Build_tree(int &now,int *num,int l,int r)
{
        now=++topt;
        int mid=(l+r)>>1;
        splay[now].siz=1;
        splay[now].sum=splay[now].val=splay[now].mx=splay[now].lx=splay[now].rx=num[mid];
        if (l<=mid-1)Build_tree(lch,num,l,mid-1);
        if (mid+1<=r)Build_tree(rch,num,mid+1,r);
        splay[lch].pnt=now;
        splay[rch].pnt=now;
        up(now);
}
int num[MAXN];
int main()
{
        freopen("input.txt","r",stdin);
        //freopen("output.txt","w",stdout);
        int i,j,k;
        int x,y,z;
        scanf("%d",&n);
        for (i=0;i<n;i++)
        {
                x=nextInt();
                num[i]=x;
        }
        Build_tree(root,num,0,n-1);
        scanf("%d
",&m);
        char opt;
        for (i=0;i<m;i++)
        {
                opt=getchar();
                //scanf("%c",&opt);
                if (opt=='I')
                {
                    //    scanf("%d%d",&x,&y);
                        x=nextInt();y=nextInt();
                        x--;
                        Insert(x,y);
                }else if (opt=='Q')
                {
                    //    scanf("%d%d",&x,&y);
                        x=nextInt();y=nextInt();
                        printf("%d
",Qry_mxs(x,y));
                }else if (opt=='R')
                {
                    //    scanf("%d%d",&x,&y);
                        x=nextInt();y=nextInt();
                        Chg_val(x,y);
                }else if (opt=='D')
                {
                    //    scanf("%d",&x);
                        x=nextInt();
                        Delete(x);
                }
                getchar();
        }
        return 0;
}

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原文地址:https://www.cnblogs.com/mhy12345/p/4029533.html