BZOJ4864 BeiJing 2017 Wc神秘物质（splay）

　　splay维护区间最大值、最小值、相邻两数差的绝对值的最小值即可。

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;
#define ll long long
#define N 100010
#define inf 2100000000
#define lson tree[k].ch[0]
#define rson tree[k].ch[1]
char getc(){char c=getchar();while ((c<'A'||c>'Z')&&(c<'a'||c>'z')&&(c<''||c>'')) c=getchar();return c;}
int gcd(int n,int m){return m==?n:gcd(m,n%m);}
int read()
{
    int x=,f=;char c=getchar();
    while (c<''||c>'') {if (c=='-') f=-;c=getchar();}
    while (c>=''&&c<='') x=(x<<)+(x<<)+(c^),c=getchar();
    return x*f;
}
int n,m,a[N],cnt,root;
struct data{int ch[],fa,x,d,s,max,min,mind;
}tree[N<<];
void up(int k)
{
    tree[k].max=max(max(tree[lson].max,tree[rson].max),tree[k].x);
    tree[k].min=min(min(tree[lson].min,tree[rson].min),tree[k].x);
    tree[k].mind=min(min(tree[lson].mind,tree[rson].mind),tree[k].d);
    tree[k].s=tree[lson].s+tree[rson].s+;
}
int build(int l,int r,int from)
{
    if (l>r) return ;
    int mid=l+r>>,k=++cnt;tree[k].fa=from;tree[k].s=;
    tree[k].x=tree[k].max=tree[k].min=a[mid];
    tree[k].d=tree[k].mind=abs(a[mid]-a[mid+]);
    lson=build(l,mid-,k),rson=build(mid+,r,k);
    up(k);
    return k;
}
int whichson(int k){return tree[tree[k].fa].ch[]==k;}
void move(int k)
{
    int fa=tree[k].fa,gf=tree[fa].fa,p=whichson(k);
    tree[gf].ch[whichson(fa)]=k,tree[k].fa=gf;
    tree[tree[k].ch[!p]].fa=fa,tree[fa].ch[p]=tree[k].ch[!p];
    tree[k].ch[!p]=fa,tree[fa].fa=k;
    up(fa),up(k);
}
void splay(int k,int rt)
{
    while (tree[k].fa!=rt)
    {
        int fa=tree[k].fa;
        if (tree[fa].fa!=rt)
            if (whichson(k)^whichson(fa)) move(k);
            else move(fa);
        move(k);
    }
    if (!rt) root=k;
}
int find(int k,int x)
{
    if (tree[lson].s==x) return k;
    else if (tree[lson].s>x) return find(lson,x);
    else return find(rson,x-tree[lson].s-);
}
void ins(int k,int x)
{
    int p=find(root,k-),q=find(root,k);
    splay(p,),splay(q,p);
    k=++cnt;tree[k].fa=q;tree[k].s=;
    tree[k].x=tree[k].max=tree[k].min=x;
    tree[k].d=tree[k].mind=abs(x-tree[q].x);
    tree[q].ch[]=k,up(q);
    tree[p].d=abs(tree[p].x-x),up(p);
}
void del(int k)
{
    int p=find(root,k-),q=find(root,k+);
    splay(p,),splay(q,p);
    tree[q].ch[]=,up(q);
    tree[p].d=abs(tree[p].x-tree[q].x),up(p);
}
int query(int l,int r,int op)
{
    int p=find(root,l-),q=find(root,r+);
    splay(p,),splay(q,p);
    int k=tree[q].ch[];
    if (op==) return tree[k].max;
    else if (op==) return tree[k].min;
    else return tree[k].mind;
}
int main()
{
#ifndef ONLINE_JUDGE
    freopen("bzoj4864.in","r",stdin);
    freopen("bzoj4864.out","w",stdout);
    const char LL[]="%I64d\n";
#else
    const char LL[]="%lld\n";
#endif
    n=read(),m=read();
    for (int i=;i<=n;i++) a[i]=read();
    tree[].max=tree[].d=-inf,tree[].min=tree[].mind=tree[].d=inf;
    root=build(,n+,);
    while (m--)
    {
        char c=getc();
        if (c=='m')
        {
            c=getc();
            if (c=='e')
            {
                int x=read(),y=read();
                del(x);del(x);ins(x,y);
            }
            else
            {
                int l=read(),r=read();
                if (c=='a') printf("%d\n",query(l,r,)-query(l,r,));
                else printf("%d\n",query(l,r-,));
            }
        }
        else
        {
            int x=read(),y=read();
            ins(x+,y);
        }
    }
    return ;
}