-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathBST.java
More file actions
174 lines (163 loc) · 4.46 KB
/
BST.java
File metadata and controls
174 lines (163 loc) · 4.46 KB
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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
package BinarySearchTree;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import java.util.Stack;
public class BST {
TreeNode root;
public BST() {
}
public void insert(int key) {
TreeNode node = new TreeNode(key);
TreeNode pre = null, runner = root;
while (runner != null) {
pre = runner;
if (runner.key == key) {
return;
}
if (key < runner.key) {
runner = runner.left;
}
else {
runner = runner.right;
}
}
node.parent = pre;
if (pre == null) {
root = node;
}
else if (pre.key < key){
pre.right = node;
}
else {
pre.left = node;
}
}
public TreeNode search(int key) {
TreeNode runner = root;
while (runner != null) {
if (key == runner.key) {
return runner;
}
if (key < runner.key) {
runner = runner.left;
}
else {
runner = runner.right;
}
}
return null;
}
public TreeNode getMinNode(TreeNode x) {
if (x == null) {
return null;
}
TreeNode runner = x;
while (runner.left != null) {
runner = runner.left;
}
return runner;
}
public TreeNode getMaxNode(TreeNode x) {
if (x == null) {
return null;
}
TreeNode runner = x;
while (runner.right != null) {
runner = runner.right;
}
return runner;
}
public TreeNode getSuccessor(TreeNode x) {
if (x == null) return null;
if (x.right != null) {
return getMinNode(x.right);
}
TreeNode p = x.parent;
while (p != null && x == p.right) {
x = p;
p = p.parent;
}
return p;
}
public TreeNode getPredecessor(TreeNode x) {
if (x == null) return null;
if (x.left != null) {
return getMaxNode(x.left);
}
TreeNode p = x.parent;
while (p != null && x == p.left) {
x = p;
p = p.parent;
}
return p;
}
public void delete(TreeNode x) {
if (x == null) return;
TreeNode splicedNode = null;
//case 1: x is leaf node;
if (x.left == null && x.right == null) {
splicedNode = x;
}
//case 2: x has only one child;
else if (x.left == null || x.right == null) {
splicedNode = x;
}
//case 3: x has two children;
else {
splicedNode = getSuccessor(x);
}
TreeNode childOfSplicedNode = null;
if (splicedNode.left != null) {
childOfSplicedNode = splicedNode.left;
}
else {
childOfSplicedNode = splicedNode.right;
}
if (childOfSplicedNode != null) {
childOfSplicedNode.parent = splicedNode.parent;
}
if (splicedNode.parent == null) {
root = childOfSplicedNode;
}
else {
if (splicedNode == splicedNode.parent.left) {
splicedNode.parent.left = childOfSplicedNode;
}
else {
splicedNode.parent.right = childOfSplicedNode;
}
}
if (splicedNode != x) {
x.key = splicedNode.key;
}
}
public void printTree() {
Queue<TreeNode> queue = new LinkedList<TreeNode>();
queue.offer(root);
int parent = 1, children = 0;
List<Integer> list = new ArrayList<Integer>();
while (!queue.isEmpty()) {
TreeNode front = queue.poll();
list.add(front.key);
if (front.left != null) {
queue.offer(front.left);
children++;
}
if (front.right != null) {
queue.offer(front.right);
children++;
}
if (--parent == 0) {
for (Integer d : list) {
System.out.print(d + " ");
}
System.out.println();
list = new ArrayList<Integer>();
parent = children;
children = 0;
}
}
}
}