bzoj4864 [BeiJing 2017 Wc]神秘物质

题目描述

题解：

splay维护区间最大最小值，以及相邻两项的最小差。

因为向集合中加入元素不能缩小极差。

还有，要换行。

PE2次。

代码：

#include<cmath>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define N 100050
#define M 200050
inline int rd()
{
    int f=1,c=0;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){c=10*c+ch-'0';ch=getchar();}
    return f*c;
}
int n,m,e[N];
const int inf = 0x3f3f3f3f;
struct Splay
{
    int mn[M],mx[M],v[M],Mn[M],L[M],R[M];
    int fa[M],ch[M][2],siz[M],rt,tot;
    Splay()
    {
        v[0]=Mn[0]=mn[0]=L[0]=R[0]=inf;
        tot = 0;
    }
    void update(int u)
    {
        int ls = ch[u][0],rs = ch[u][1];
        siz[u] = siz[ls]+siz[rs]+1;
        mn[u]=min(min(mn[ls],mn[rs]),v[u]);
        mx[u]=max(max(mx[ls],mx[rs]),v[u]);
        Mn[u]=inf;
        if(ls)Mn[u] = min(Mn[u],min(Mn[ls],abs(v[u]-R[ls])));
        if(rs)Mn[u] = min(Mn[u],min(Mn[rs],abs(v[u]-L[rs])));
        if(ls)L[u] = L[ls];
        else L[u]=v[u];
        if(rs)R[u] = R[rs];
        else R[u]=v[u];
    }
    void rotate(int x)
    {
        int y = fa[x],z = fa[y],k = (ch[y][1]==x);
        ch[y][k]=ch[x][!k],fa[ch[x][!k]]=y;
        ch[x][!k]=y,fa[y]=x;
        ch[z][ch[z][1]==y]=x,fa[x]=z;
        update(y),update(x);
    }
    void splay(int x,int goal)
    {
        while(fa[x]!=goal)
        {
            int y = fa[x],z = fa[y];
            if(z!=goal)
                (ch[y][1]==x)^(ch[z][1]==y)?rotate(x):rotate(y);
            rotate(x);
        }
        if(!goal)rt=x;
    }
    int build(int l,int r,int f)
    {
        if(l>r)return 0;
        int mid = (l+r)>>1;
        int x = ++tot;
        fa[x]=f;
        L[x]=R[x]=v[x]=e[mid];
        Mn[x]=inf;
        ch[x][0]=build(l,mid-1,x);
        ch[x][1]=build(mid+1,r,x);
        update(x);
        return x;
    }
    int get_pnt(int x,int k)
    {
        int tmp = siz[ch[x][0]];
        if(k<=tmp)return get_pnt(ch[x][0],k);
        else if(k==tmp+1)return x;
        else return get_pnt(ch[x][1],k-1-tmp);
    }
    void Merge(int x,int d)
    {
        int x1 = get_pnt(rt,x);
        int x2 = get_pnt(rt,x+3);
        splay(x1,0);splay(x2,x1);
        x = ++tot;
        siz[x] = 1;
        fa[x] = x2;ch[x2][0] = x;
        v[x] = mn[x] = mx[x] = L[x] = R[x] = d;
        Mn[x] = inf;
        update(x2),update(x1);
    }
    void Insert(int x,int d)
    {
        int x1 = get_pnt(rt,x+1);
        int x2 = get_pnt(rt,x+2);
        splay(x1,0);splay(x2,x1);
        x = ++tot;
        siz[x] = 1;
        fa[x] = x2;ch[x2][0] = x;
        v[x] = mn[x] = mx[x] = L[x] = R[x] = d;
        Mn[x] = inf;
        update(x2),update(x1);
    }
    int Max(int x,int y)
    {
        x = get_pnt(rt,x);
        y = get_pnt(rt,y+2);
        splay(x,0);splay(y,x);
        return mx[ch[y][0]]-mn[ch[y][0]];
    }
    int Min(int x,int y)
    {
        x = get_pnt(rt,x);
        y = get_pnt(rt,y+2);
        splay(x,0);splay(y,x);
        return Mn[ch[y][0]];
    }
}tr;
char opt[10];
int main()
{
    n=rd(),m=rd();
    e[1]=e[n+2]=inf;
    for(int i=2;i<=n+1;i++)e[i]=rd();
    tr.rt = tr.build(1,n+2,0);
    for(int x,y,i=1;i<=m;i++)
    {
        scanf("%s",opt+1);
        x = rd(),y = rd();
        if(opt[2]=='e')
        {
            tr.Merge(x,y);
        }else if(opt[2]=='n')
        {
            tr.Insert(x,y);
        }else if(opt[2]=='a')
        {
            printf("%d
",tr.Max(x,y));
        }else
        {
            printf("%d
",tr.Min(x,y));
        }
    }
//    puts("");
    return 0;
}