P3369 【模板】普通平衡树(Splay)

题目链接：https://www.luogu.org/problemnew/show/P3369

修改了一下之前的模板，支持重复数值的存储

 #include<bits/stdc++.h>
 using namespace std;
 struct node
 {
     int val;
     node *father;
     node *son[];
     int cnt;
     int siz;
 } tree[],*root;
 inline void init(node *p,int val=)
 {
     p->father=NULL;
     p->son[]=p->son[]=NULL;
     p->val=val;
     p->siz=;
     p->cnt=;
 }
 inline int siz(node *t)
 {
     return t == NULL ?  : t->siz;
 }
 inline void update(node *t)//rotate与erase操作时需更新
 {
     t->siz = t->cnt;
     t->siz += siz(t->son[]);
     t->siz += siz(t->son[]);
 }
 inline bool son(node *f, node *s)
 {
     return f->son[] == s;
 }
 inline void rotate(node *t)
 {
     node *f = t->father;
     node *g = f->father;
     bool a = son(f, t), b = !a;
     f->son[a] = t->son[b];
     if (t->son[b] != NULL)
         t->son[b]->father = f;
     t->son[b] = f;
     f->father = t;
     t->father = g;
     if (g != NULL)
         g->son[son(g, f)] = t;
     else
         root = t;
     update(t);
     update(f);
 }
 inline void splay(node *t, node *p)
 {
     while (t->father != p)
     {
         node *f = t->father;
         node *g = f->father;
         if (g == p)
             rotate(t);
         else
         {
             if (son(g, f) ^ son(f, t))
                 rotate(t), rotate(t);
             else
                 rotate(f), rotate(t);
         }
     }
     update(t);
     if(p!=NULL) update(p);
 }
 inline void insert(node* p)
 {
     if (root == NULL)
     {
         root = p;
         return;
     }
     for(node* t=root; t; t = t->son[t->val < p->val])
     {
         if(t->val==p->val)
         {
             t->cnt++;
             splay(t,NULL);
             return;
         }
         if(t->son[t->val < p->val]==NULL)
         {
             t->son[t->val < p->val]=p;
             p->father=t;
             splay(p,NULL);
             return;
         }
     }
 }
 inline void erase(node *t)
 {
     splay(t,NULL);
     if (t->son[] == NULL)
     {
         root = t->son[];
         if (root != NULL)
             root->father = NULL;
     }
     else
     {
         node *p = t->son[];
         while (p->son[] != NULL)
             p = p->son[];
         splay(p, t);
         root = p;
         root->father = NULL;
         p->son[] = t->son[];
         if (p->son[] != NULL)
             p->son[]->father = p;
         update(p);
     }
 }
 int n,m;
 bool flag;
 inline node* findx(int kth)
 {
     node* p=root;
     while()
     {
         if(kth<=siz(p->son[])) p=p->son[];
         else
         {
             kth-=siz(p->son[])+p->cnt;
             if(kth<=) return p;
             p=p->son[];
         }
     }
 }
 inline node* findkth(int x)
 {
     node* p=root;
     while()
     {
         if(p==NULL) return NULL;
         if(p->val==x) return p;
         p=p->son[p -> val < x];
     }
 }
 int main()
 {
     int m;
     scanf("%d",&m);
     int tot=;
     for(int i=;i<=m;i++)
     {
         int op;
         scanf("%d",&op);
         if(op==)
         {
             int x;
             scanf("%d",&x);
             init(&tree[++tot],x);
             insert(&tree[tot]);
         }
         if(op==)
         {
             int x;
             scanf("%d",&x);
             node* tmp=findkth(x);
             if(tmp!=NULL)
             {
                 tmp->cnt--;
                 if(!tmp->cnt)
                     erase(tmp);
                 else
                     splay(tmp,NULL);
             }
         }
         if(op==)
         {
             int x;
             scanf("%d",&x);
             node* tmp=findkth(x);
             splay(tmp,NULL);
             if(tmp->son[]==NULL)
                 puts("");
             else
                 printf("%d\n",tmp->son[]->siz+);
         }
         if(op==)
         {
             int kth;
             scanf("%d",&kth);
             node *tmp=findx(kth);
             if(tmp!=NULL) printf("%d\n",tmp->val);
         }
         if(op==)
         {
             int x;
             scanf("%d",&x);
             node* p=root;
             int tmp;
             while()
             {
                 if(p==NULL) break;
                 if(p->val>=x)
                     p=p->son[];
                 else
                 {
                     tmp=p->val;
                     p=p->son[];
                 }
             }
             printf("%d\n",tmp);
         }
         if(op==)
         {
             int x;
             scanf("%d",&x);
             node* p=root;
             int tmp;
             while()
             {
                 if(p==NULL) break;
                 if(p->val<=x)
                     p=p->son[];
                 else
                 {
                     tmp=p->val;
                     p=p->son[];
                 }
             }
             printf("%d\n",tmp);
         }
     }
 }