1 /**************************************************
2 Target: Treap
3 Author: Xue Zhonghao
4 Date: 2014-4-3 17:53:22
5 **************************************************/
6 #include<cstdio>
7 #include<iostream>
8 //#include<fstream>
9 using namespace std;
10 //ifstream fin("input.txt");
11 //ofstream fout("output.txt");
12
13 //#define cin fin
14 //#define cout fout
15
16 #define LL long long
17
18 struct Node {
19 Node *ch[2];
20 int r;//heap value
21 LL v;//tree value
22 LL cmp(LL x) const {
23 if(x == v) return -1;
24 return x < v ? 0 : 1;
25 }
26 };
27
28 //0 left rotate | 1 right rotate
29 void rotate(Node* &o, int d) {
30 Node *k = o->ch[d^1]; o->ch[d^1] = k->ch[d]; k->ch[d] = o; o = k;
31 }
32
33 void insert(Node* &o, LL x) {
34 if(o == NULL) { o = new Node(); o->ch[0] = o->ch[1] = NULL; o->v = x; o -> r = rand(); }
35 else {
36 int d = o->cmp(x);
37 insert(o->ch[d], x); if(o->ch[d] ->r > o->r) rotate(o, d^1);;
38 }
39 }
40
41 void remove(Node* &o, LL x) {
42 if(o == NULL) { cout<<"Delete failed"<<endl; return; }
43 int d = o->cmp(x);
44 if(d == -1) {
45 if(o->ch[0] == NULL) o = o->ch[1];
46 else if(o->ch[1] == NULL) o = o->ch[0];
47 else {
48 int d2 = (o->ch[0] ->r > o->ch[1] ->r ? 1 : 0);
49 rotate(o, d2); remove(o->ch[d2], x);
50 }
51 }
52 else
53 remove(o->ch[d], x);
54 }
55
56 int find(Node* o, LL x) {
57 while(o != NULL) {
58 int d = o->cmp(x);
59 if(d == -1) return 1;
60 else o = o->ch[d];
61 }
62 return 0;
63 }
64
65 int main(void)
66 {
67 Node* root = NULL;
68 char ch;
69 LL x;
70 int d;
71 while(1) {
72 do cin>>ch; while (ch == ' ' || ch == '\n');
73 if(ch == 'I') {
74 cin>>x;
75 d = find(root, x);
76 if(!d) insert(root, x);
77 else cout<<"Insert failed"<<endl;
78 }
79 else if(ch == 'D') {
80 cin>>x;
81 remove(root, x);
82 }
83 else if(ch == 'Q') {
84 cin>>x;
85 d = find(root, x);
86 if(d) cout<<"Yes"<<endl;
87 else cout<<"No"<<endl;
88 }
89 else if(ch == 'C') break;
90 }
91 return 0;
92 }
