題目鏈接：https://www.luogu.org/problemnew/show/P3369

修改了一下之前的模板，支持重復數值的存儲

  1 #include<bits/stdc++.h>
  2 using namespace std;
  3 struct node
  4 {
  5     int val;
  6     node *father;
  7     node *son[2];
  8     int cnt;
  9     int siz;
 10 } tree[100005],*root;
 11 inline void init(node *p,int
 
 val=0)
 12 {
 13     p->father=NULL;
 14     p->son[0]=p->son[1]=NULL;
 15     p->val=val;
 16     p->siz=1;
 17     p->cnt=1;
 18 }
 19 inline int siz(node *t)
 20 {
 21     return t == NULL ? 0 : t->siz;
 22 }
 23 inline void update(node *t)//rotate與erase操作時需更新
 24 {
 
 25     t->siz = t->cnt;
 26     t->siz += siz(t->son[0]);
 27     t->siz += siz(t->son[1]);
 28 }
 29 inline bool son(node *f, node *s)
 30 {
 31     return f->son[1] == s;
 32 }
 33 inline void rotate(node *t)
 34 {
 35     node *f = t->father;
 36     node *g = f->father;
 
 37     bool a = son(f, t), b = !a;
 38     f->son[a] = t->son[b];
 39     if (t->son[b] != NULL)
 40         t->son[b]->father = f;
 41     t->son[b] = f;
 42     f->father = t;
 43     t->father = g;
 44     if (g != NULL)
 45         g->son[son(g, f)] = t;
 46     else
 47         root = t;
 48     update(t);
 49     update(f);
 50 }
 51 inline void splay(node *t, node *p)
 52 {
 53     while (t->father != p)
 54     {
 55         node *f = t->father;
 56         node *g = f->father;
 57         if (g == p)
 58             rotate(t);
 59         else
 60         {
 61             if (son(g, f) ^ son(f, t))
 62                 rotate(t), rotate(t);
 63             else
 64                 rotate(f), rotate(t);
 65         }
 66     }
 67 }
 68 inline void insert(node* p)
 69 {
 70     if (root == NULL)
 71     {
 72         root = p;
 73         return;
 74     }
 75     for(node* t=root; t; t = t->son[t->val < p->val])
 76     {
 77         t->siz++;
 78         if(t->val==p->val)
 79         {
 80             t->cnt++;
 81             splay(t,NULL);
 82             return;
 83         }
 84         if(t->son[t->val < p->val]==NULL)
 85         {
 86             t->son[t->val < p->val]=p;
 87             p->father=t;
 88             splay(p,NULL);
 89             return;
 90         }
 91     }
 92 }
 93 inline void erase(node *t)
 94 {
 95     splay(t,NULL);
 96     if (t->son[0] == NULL)
 97     {
 98         root = t->son[1];
 99         if (root != NULL)
100             root->father = NULL;
101     }
102     else
103     {
104         node *p = t->son[0];
105         while (p->son[1] != NULL)
106             p = p->son[1];
107         splay(p, t);
108         root = p;
109         root->father = NULL;
110         p->son[1] = t->son[1];
111         if (p->son[1] != NULL)
112             p->son[1]->father = p;
113         update(p);
114     }
115 }
116 int n,m;
117 bool flag;
118 inline node* findx(int kth)
119 {
120     node* p=root;
121     while(1)
122     {
123         if(kth<=siz(p->son[0])) p=p->son[0];
124         else
125         {
126             kth-=siz(p->son[0])+p->cnt;
127             if(kth<=0) return p;
128             p=p->son[1];
129         }
130     }
131 }
132 inline node* findkth(int x)
133 {
134     node* p=root;
135     while(1)
136     {
137         if(p==NULL) return NULL;
138         if(p->val==x) return p;
139         p=p->son[p -> val < x];
140     }
141 }
142 int main()
143 {
144     int m;
145     scanf("%d",&m);
146     int tot=0;
147     for(int i=1;i<=m;i++)
148     {
149         int op;
150         scanf("%d",&op);
151         if(op==1)
152         {
153             int x;
154             scanf("%d",&x);
155             init(&tree[++tot],x);
156             insert(&tree[tot]);
157         }
158         if(op==2)
159         {
160             int x;
161             scanf("%d",&x);
162             node* tmp=findkth(x);
163             if(tmp!=NULL)
164             {
165                 tmp->cnt--;
166                 if(!tmp->cnt)
167                     erase(tmp);
168                 else
169                     splay(tmp,NULL);
170             }
171         }
172         if(op==3)    
173         {
174             int x;
175             scanf("%d",&x);
176             node* tmp=findkth(x);
177             splay(tmp,NULL);
178             if(tmp->son[0]==NULL)
179                 puts("1");
180             else
181                 printf("%d\n",tmp->son[0]->siz+1);
182         }
183         if(op==4)
184         {
185             int kth;
186             scanf("%d",&kth);
187             node *tmp=findx(kth);
188             if(tmp!=NULL) printf("%d\n",tmp->val);
189         }
190         if(op==5)
191         {
192             int x;
193             scanf("%d",&x);
194             node* p=root;
195             int tmp;
196             while(1)
197             {
198                 if(p==NULL) break;
199                 if(p->val>=x)
200                     p=p->son[0];
201                 else
202                 {
203                     tmp=p->val;
204                     p=p->son[1];
205                 }
206             }
207             printf("%d\n",tmp);
208         }
209         if(op==6)
210         {
211             int x;
212             scanf("%d",&x);
213             node* p=root;
214             int tmp;
215             while(1)
216             {
217                 if(p==NULL) break;
218                 if(p->val<=x)
219                     p=p->son[1];
220                 else
221                 {
222                     tmp=p->val;
223                     p=p->son[0];
224                 }
225             }
226             printf("%d\n",tmp);
227         }
228     }
229 }

P3369 【模板】普通平衡樹(Splay)