package ThirdWork class Node public int key public int height public N

  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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
package ThirdWork;
class Node {
public int key;
public int height;
public Node left;
public Node right;
public Node(int key) {
this.key = key;
height = 1;
}
}
public class AVLTree {
private Node root;
public AVLTree() {
root = null;
}
public Node getRoot() {
return root;
}
public Node find(int key, Node root) {
if (root == null)
return null;
else if (root.key == key)
return root;
else if (root.key < key)
return find(key, root.right);
else
return find(key, root.left);
}
public int height(Node x) {
if (x == null) return 0;
else return x.height;
}
private Node rotateRight(Node p) {
Node q = p.left;
p.left = q.right;
q.right = p;
fixHeight(p);
fixHeight(q);
return q;
}
private Node rotateLeft(Node q) {
Node p = q.right;
q.right = p.left;
p.left = q;
fixHeight(q);
fixHeight(p);
return p;
}
public void insert(int key) {
if (root == null)
root = new Node(key);
else {
root = insert(root, key);
}
}
private Node insert(Node p, int key) {
if (p == null) return new Node(key);
if (key < p.key) {
p.left = insert(p.left, key);
}
else {
p.right = insert(p.right, key);
}
return balance(p);
}
private Node findMin(Node p) {
return p.left == null ? p : findMin(p.left);
}
private Node removeMin(Node p) {
if (p.left == null) {
return p.right;
}
p.left = removeMin(p.left);
return balance(p);
}
public void remove(int key) {
remove(root, key);
}
private Node remove(Node p, int key) {
if (p == null) return null;
if (key < p.key) {
p.left = remove(p.left, key);
}
else if (key > p.key){
p.right = remove(p.right, key);
}
else {
Node q = p.left;
Node r = p.right;
p = null;
if (r == null) return q;
Node min = findMin(r);
min.right = removeMin(r);
min.left = q;
return balance(min);
}
return balance(p);
}
private Node balance(Node p) {
fixHeight(p);
if (balanceFactor(p) == 2) {
if (balanceFactor(p.right) < 0) {
p.right = rotateRight(p.right);
}
return rotateLeft(p);
}
if (balanceFactor(p) == -2 ){
if (balanceFactor(p.left) > 0) {
p.left = rotateLeft(p.left);
}
return rotateRight(p);
}
return p;
}
private void fixHeight(Node p) {
p.height = Math.max(height(p.left), height(p.right)) + 1;
}
private int balanceFactor(Node p) {
return height(p.right) - height(p.left);
}
}