-
Notifications
You must be signed in to change notification settings - Fork 1
/
BST.cpp
133 lines (112 loc) · 2.21 KB
/
BST.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
#include "BST.h"
#include <math.h>
#define delta 1e-6
//public functions
void BST::insert(const double key)
{
insert(key, root);
}
void BST::remove(const double key)
{
remove(key, root);
}
double BST::select(int k)
{
return select(k, root);
}
void BST::removeAll()
{
removeAll(root);
}
int BST::getSize() //return the size of the whole tree
{
return root->size;
}
//private functions
int BST::getSize(pNode &rt)
{
if (!rt)
return 0;
else
return rt->size;
}
void BST::insert(const double key, pNode &rt)
{
if (!rt) {
rt = new node();
rt->value = key;
rt->number = rt->size = 1;
rt->L = rt->R = NULL;
return;
}
if (fabs(rt->value - key) < delta) { //rt->value == key
rt->number++;
rt->size++;
return;
}
if (key < rt->value) {
insert(key, rt->L);
if (rt->L->weight < rt->weight) //maintain heap feature
leftRotate(rt);
}
else {
insert(key, rt->R);
if (rt->R->weight < rt->weight) //maintain heap feature
rightRotate(rt);
}
rt->size = getSize(rt->L) + getSize(rt->R) + rt->number; //update the subtree size.
}
void BST::remove(const double key, pNode &rt)
{
if (!rt)
return;
if (fabs(rt->value - key) < delta) { //rt->value == key
if (rt->number > 0) {
rt->number--;
rt->size--;
}
return;
}
if (key < rt->value)
remove(key, rt->L);
else
remove(key, rt->R);
rt->size = getSize(rt->L) + getSize(rt->R) + rt->number;
}
double BST::select(int k, pNode &rt)
{
int lSize = getSize(rt->L);
if (k > lSize && k <= lSize + rt->number)
return rt->value;
else if (k <= lSize)
return select(k, rt->L);
else
return select(k - lSize - rt->number, rt->R);
}
void BST::removeAll(pNode &rt)
{
if (!rt)
return;
removeAll(rt->L);
removeAll(rt->R);
delete rt;
rt = NULL;
}
void BST::leftRotate(pNode &rt)
{
pNode p = rt->L;
rt->L = p->R;
p->R = rt;
rt->size = rt->L->size + rt->R->size + rt->number;
p->size = rt->size + p->L->size + p->number;
rt = p;
}
void BST::rightRotate(pNode &rt)
{
pNode p = rt->R;
rt->R = p->L;
p->L = rt;
rt->size = rt->L->size + rt->R->size + rt->number;
p->size = rt->size + p->R->size + p->number;
rt = p;
}