Treap

 1 #include <iostream>
 2 #include <cstdlib>
 3 #include <cstring>
 4 #include <queue>
 5 #include <cstdio>
 6 #include <algorithm>
 7 #include <map>
 8 #define LL long long
 9 
10 using namespace std;
11 
12 struct Treap_node
13 {
14     Treap_node *left,*right;
15     int value,fix; //the value and the random fix value
16 }*root;
17 
18 void Treap_left_rotate(Treap_node *&a)
19 {
20     Treap_node *b = a->right;
21     a->right = b->left;
22     b->left = a;
23     a = b;
24 }
25 
26 void Treap_right_rotate(Treap_node *&a)
27 {
28     Treap_node *b = a->left;
29     a->left = b->right;
30     b->right = a;
31     a = b;
32 }
33 
34 void Treap_insert(Treap_node*&p, int value)
35 {
36     if(!p)
37     {
38         p = new Treap_node;
39         p->value = value;
40         p->fix = rand();
41         p->left = p->right = NULL;
42     }
43     else if(value <= p->value)
44     {
45         Treap_insert(p->left,value);
46         if(p->left->fix < p->fix)
47             Treap_right_rotate(p);
48     }
49     else
50     {
51         Treap_insert(p->right,value);
52         if(p->right->fix < p->fix)
53             Treap_left_rotate(p);
54     }
55 }
56 
57 void Treap_delete(Treap_node* &p,int value)
58 {
59     if(value < p->value)
60         Treap_delete(p->left,value);
61     else if(value > p->value)
62         Treap_delete(p->right,value);
63     else
64     {
65         if(!p->right || !p->left) //link nodes or have no child node
66         {
67             Treap_node *t;
68             t = p;
69             if(!p->right)
70                 p = p->left;
71             else
72                 p = p->right;
73             delete t;
74         }
75         else
76         {
77             if(p->left->fix < p->right->fix)
78             {
79                 Treap_right_rotate(p);
80                 Treap_delete(p->right,value);
81             }
82             else
83             {
84                 Treap_left_rotate(p);
85                 Treap_delete(p->left,value);
86             }
87         }
88     }
89 }