[BZOJ4864][BeiJing2017Wc]神秘物质(splay)

首先merge就是先delete两次再insert，Max就是整个区间的最大值减最小值，Min就是区间中所有相邻两数差的最小值。

Splay支持区间最大值，区间最小值，区间相邻差最小值即可。

 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #define rep(i,l,r) for (int i=(l); i<=(r); i++)
 using namespace std;

 const int N=,inf=1e9;
 char op[];
 int n,m,nd,rt,x,y,v[N],d[N],sz[N],mx[N],mn[N],mnd[N],a[N],ch[N][],f[N];

 int Abs(int x){ return x< ? -x : x; }

 void upd(int x){
     int ls=ch[x][],rs=ch[x][];
     sz[x]=sz[ls]+sz[rs]+;
     mn[x]=min(v[x],min(mn[ls],mn[rs]));
     mx[x]=max(v[x],max(mx[ls],mx[rs]));
     mnd[x]=min(d[x],min(mnd[ls],mnd[rs]));
 }

 void rot(int &rt,int x){
     int y=f[x],z=f[y],w=ch[y][]==x;
     if (y==rt) rt=x; else ch[z][ch[z][]==y]=x;
     f[y]=x; f[x]=z; f[ch[x][w^]]=y;
     ch[y][w]=ch[x][w^]; ch[x][w^]=y; upd(y);
 }

 void splay(int &rt,int x){
     while (x!=rt){
         int y=f[x],z=f[y];
         if (y!=rt) (ch[z][]==y ^ ch[y][]==x) ? rot(rt,x) : rot(rt,y);
         rot(rt,x);
     }
     upd(x);
 }

 int build(int l,int r){
     if (l>r) return ;
     int x=++nd,mid=(l+r)>>;
     v[x]=a[mid]; d[x]=Abs(a[mid]-a[mid-]); sz[x]=;
     f[ch[x][]=build(l,mid-)]=x; f[ch[x][]=build(mid+,r)]=x;
     upd(x); return x;
 }

 int find(int x,int k){
     if (sz[ch[x][]]+==k) return x;
     if (k<=sz[ch[x][]]) return find(ch[x][],k);
         else return find(ch[x][],k-sz[ch[x][]]-);
 }

 void ins(int p,int k){
     int x=find(rt,p+),y=find(rt,p+);
     splay(rt,x); splay(ch[x][],y);
     v[++nd]=k; d[nd]=Abs(v[nd]-v[x]); f[nd]=y; sz[nd]=;
     ch[y][]=nd; d[y]=Abs(v[y]-v[nd]); upd(nd); upd(y); upd(x);
 }

 void del(int p){
     int x=find(rt,p),y=find(rt,p+);
     splay(rt,x); splay(ch[x][],y);
     ch[y][]=; d[y]=Abs(v[y]-v[x]); upd(y); upd(x);
 }

 int que(int l,int r,int op){
     int x=find(rt,l),y=find(rt,r+);
     splay(rt,x); splay(ch[x][],y);
     return op== ? mx[ch[y][]] : (op== ? mn[ch[y][]] : mnd[ch[y][]]);
 }

 int main(){
     freopen("bzoj4864.in","r",stdin);
     freopen("bzoj4864.out","w",stdout);
     scanf("%d%d",&n,&m); mnd[]=mn[]=inf;
     rep(i,,n) scanf("%d",&a[i]);
     rt=build(,n+);
     rep(i,,m){
         scanf("%s%d%d",op,&x,&y);
         if (op[]=='e') del(x),del(x),ins(x-,y);
         if (op[]=='n') ins(x,y);
         if (op[]=='a') printf("%d\n",que(x,y,)-que(x,y,));
         if (op[]=='i') printf("%d\n",que(x+,y,));
     }
     return ;
 }