网上有关于二叉数的java实现http://blog.csdn.net/skylinesky/article/details/6611442
多数案例都没有键值，有键值的也全是整型。我用java实现了一个可以任何对象为键的二叉数
package Tree;
import java.io.IOException;
public class Tree<I extends Comparable<I> ,V> {
@SuppressWarnings("rawtypes")
private Node root;
@SuppressWarnings("unchecked")
public Node<I, V> getRoot() {
return root;
}
public void setRoot(Node<I, V> root) {
this.root = root;
}
//向树添加节点
@SuppressWarnings({ "unchecked" })
public void add(I index,V value){
if(root == null){
root = new Node<I, V>(index,value);
System.out.println(root);
}else{
Node<I, V> current = root;
Node<I, V> parent = null;
while(true){
parent = current;
int result = index.compareTo(current.getIndex());
if(result < 0){
current = current.getLeft();
if(current == null){
current = new Node<I, V>(index,value);
parent.setLeft(current);
return ;
}
}else{
current = current.getRight();
if(current == null){
current = new Node<I, V>(index,value);
parent.setRight(current);
return ;
}
}
}
}
}
//查找
@SuppressWarnings("unchecked")
public Node<I, V> find(I index){
Node<I, V> current = root;
int result = index.compareTo(current.getIndex());
while(result != 0){
if(result < 0){
current = current.getLeft();
}else {
current = current.getRight();
}
if(current == null){
return null;
}
result = index.compareTo(current.getIndex());
}
return current;
}
//中序遍历
public void centerTraversal(Node<I, V> node){
if(node != null){
centerTraversal(node.getLeft());
System.out.println(node);
centerTraversal(node.getRight());
}
}
//前序遍历
public void leftTraversal(Node<I, V> node){
if(node != null){
System.out.println(node);
centerTraversal(node.getLeft());
centerTraversal(node.getRight());
}
}
//后序遍历
public void rightTraversal(Node<I, V> node){
if(node != null){
System.out.println(node);
centerTraversal(node.getLeft());
centerTraversal(node.getRight());
}
}
@SuppressWarnings("unchecked")
public void delete(I index){
Node<I, V> current = root;
boolean isLeft = true;
Node<I, V> parent = null;
int result = index.compareTo(current.getIndex());
//找到要删除的结点
while(result != 0){
parent = current;
System.out.println(current.getIndex());
if(result < 0){
current = current.getLeft();
isLeft = true;
}else {
current = current.getRight();
isLeft = false;
}
if(current == null){
throw new RuntimeException(" \"" + index + "\" 没有这个节点");
}
result = index.compareTo(current.getIndex());
}
//这个要删除的节点没有子结点
if(current.getLeft() == null && current.getRight() == null){
if(current == root){
root = null;
}else{
if(isLeft){
parent.setLeft(null);
}else{
parent.setLeft(null);
}
}
}else if(current.getRight() == null){
//只有左子结点
if(current == root){
root = root.getLeft();
}else{
if(isLeft){
parent.setLeft(current.getLeft());
}else{
parent.setRight(current.getLeft());
}
}
//只有右子结点
}else if(current.getLeft() == null){
if(current == root){
root = root.getRight();
}else{
if(isLeft){
parent.setLeft(current.getRight());
}else{
parent.setRight(current.getRight());
}
}
}else{
//左右子节点都有的情况下，
Node<I,V> follow = current;
Node<I,V> followParent = follow;
Node<I,V> followCurrent = follow.getRight();
if(followCurrent.getLeft() == null){
if(isLeft){
parent.setLeft(current.getRight());
}else{
parent.setRight(current.getRight());
}
current.getRight().setLeft(current.getLeft());
}else{
while(followCurrent != null){
followParent = follow;
follow = followCurrent;
followCurrent = followCurrent.getLeft();
}
followParent.setLeft(follow.getRight());
if(isLeft){
parent.setLeft(follow);
}else{
parent.setRight(follow);
}
follow.setLeft(current.getLeft());
follow.setRight(current.getRight());
}
}
}
public static void main(String[] args) throws IOException{
Tree<Integer,Double> tree = new Tree<Integer,Double>();
tree.add(50, 1.5);
tree.add(25, 1.2);
tree.add(75, 1.7);
tree.add(12, 1.5);
tree.add(37, 1.2);
tree.add(43, 1.7);
tree.add(30, 1.5);
tree.add(33, 1.2);
tree.add(87, 1.7);
tree.add(93, 1.5);
tree.add(97, 1.5);
tree.leftTraversal(tree.getRoot());
System.out.println();
tree.delete(30);
tree.centerTraversal(tree.getRoot());
System.out.println();
tree.rightTraversal(tree.getRoot());
System.out.println();
}
}
package Tree;
public class Node<I extends Comparable<I> ,V> {
//节点的关键字
private I index;
//节点的值
private V value;
private Node<I,V> left;
private Node<I,V> right;
public Node(){
}
public Node(I index,V value){
this(index,value,null,null);
}
public Node(I index,V value,Node<I,V> left,Node<I,V> right){
this.index = index;
this.value = value;
this.left = left;
this.right = right;
}
public I getIndex() {
return index;
}
public void setIndex(I index) {
this.index = index;
}
public V getValue() {
return value;
}
public void setValue(V value) {
this.value = value;
}
public Node<I, V> getLeft() {
return left;
}
public void setLeft(Node<I, V> left) {
this.left = left;
}
public Node<I, V> getRight() {
return right;
}
public void setRight(Node<I, V> right) {
this.right = right;
}
@Override
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append(" { left:").append("[index:").append(left!=null?left.index:"null").append(" , value:").append(left!=null?left.value:"null").append("] } ")
.append(" { self:").append("[index:").append(index).append(", value:").append(value).append("] } ")
.append(" { right:").append("[index:").append(right!=null?right.index:"null").append(", value:").append(right!=null?right.value:"null").append("] } ");
return sb.toString();
}
public static void main(String args[]){
Node<String,String> root = new Node<String,String>();
root.index = "父节点";
root.value = "啊哈";
Node<String,String> left = new Node<String,String>();
left.index = "左节点";
left.value = "你妹";
Node<String,String> right = new Node<String,String>();
right.index = "右节点";
right.value = "我妹";
//root.left = left;
//root.right = right;
System.out.println(root);
}
}
原文地址：http://blog.csdn.net/zhangxiango/article/details/27691601
