标签：java 算法
节点：
/*
* 二叉树节点
*/
public class Node {
//数据项
public long data;
//数据项
public String sData;
//左子节点
public Node leftChild;
//右子节点
public Node rightChild;
/**
* 构造方法
* @param data
*/
public Node(long data,String sData) {
this.data = data;
this.sData = sData;
}
}
二叉树：
/*
* 二叉树类
*/
public class Tree {
//根节点
public Node root;
/**
* 插入节点
* @param value
*/
public void insert(long value,String sValue) {
//封装节点
Node newNode = new Node(value,sValue);
//引用当前节点
Node current = root;
//引用父节点
Node parent;
//如果root为null，也就是第一插入的时候
if(root == null) {
root = newNode;
return;
} else {
while(true) {
//父节点指向当前节点
parent = current;
//如果当前指向的节点数据比插入的要大,则向左走
if(current.data > value) {
current = current.leftChild;
if(current == null) {
parent.leftChild = newNode;
return;
}
} else {
current = current.rightChild;
if(current == null) {
parent.rightChild = newNode;
return;
}
}
}
}
}
/**
* 查找节点
* @param value
*/
public Node find(long value) {
//引用当前节点，从根节点开始
Node current = root;
//循环，只要查找值不等于当前节点的数据项
while(current.data != value) {
//进行比较，比较查找值和当前节点的大小
if(current.data > value) {
current = current.leftChild;
} else {
current = current.rightChild;
}
//如果查找不到
if(current == null) {
return null;
}
}
return current;
}
/**
* 删除节点
* @param value
*/
public boolean delete(long value) {
//引用当前节点，从根节点开始
Node current = root;
//应用当前节点的父节点
Node parent = root;
//是否为左节点
boolean isLeftChild = true;
while(current.data != value) {
parent = current;
//进行比较，比较查找值和当前节点的大小
if(current.data > value) {
current = current.leftChild;
isLeftChild = true;
} else {
current = current.rightChild;
isLeftChild = false;
}
//如果查找不到
if(current == null) {
return false;
}
}
//删除叶子节点，也就是该节点没有子节点
if(current.leftChild == null && current.rightChild == null) {
if(current == root) {
root = null;
} else if(isLeftChild) {
parent.leftChild = null;
} else {
parent.rightChild = null;
}
} else if(current.rightChild == null) {
if(current == root) {
root = current.leftChild;
}else if(isLeftChild) {
parent.leftChild = current.leftChild;
} else {
parent.rightChild = current.leftChild;
}
} else if(current.leftChild == null) {
if(current == root) {
root = current.rightChild;
} else if(isLeftChild) {
parent.leftChild = current.rightChild;
} else {
parent.rightChild = current.rightChild;
}
} else {
Node successor = getSuccessor(current);
if(current == root) {
root = successor;
} else if(isLeftChild) {
parent.leftChild = successor;
} else{
parent.rightChild = successor;
}
successor.leftChild = current.leftChild;
}
return true;
}
public Node getSuccessor(Node delNode) {
Node successor = delNode;
Node successorParent = delNode;
Node current = delNode.rightChild;
while(current != null) {
successorParent = successor;
successor = current;
current = current.leftChild;
}
if(successor != delNode.rightChild) {
successorParent.leftChild = successor.rightChild;
successor.rightChild = delNode.rightChild;
}
return successor;
}
/**
* 前序遍历
*/
public void frontOrder(Node localNode) {
if(localNode != null) {
//访问根节点
System.out.println(localNode.data + ", " + localNode.sData);
//前序遍历左子树
frontOrder(localNode.leftChild);
//前序遍历右子树
frontOrder(localNode.rightChild);
}
}
/**
* 中序遍历
*/
public void inOrder(Node localNode) {
if(localNode != null) {
//中序遍历左子树
inOrder(localNode.leftChild);
//访问根节点
System.out.println(localNode.data + ", " + localNode.sData);
//中旬遍历右子树
inOrder(localNode.rightChild);
}
}
/**
* 后序遍历
*/
public void afterOrder(Node localNode) {
if(localNode != null) {
//后序遍历左子树
afterOrder(localNode.leftChild);
//后序遍历右子树
afterOrder(localNode.rightChild);
//访问根节点
System.out.println(localNode.data + ", " + localNode.sData);
}
}
}
测试：
public class TestTree {
public static void main(String[] args) {
Tree tree = new Tree();
tree.insert(10,"James");
tree.insert(20,"YAO");
tree.insert(15,"Kobi");
tree.insert(3,"Mac");
tree.insert(4, "Zhangsan");
tree.insert(90, "Lisi");
tree.delete(90);
tree.inOrder(tree.root);
}
}
本文出自 “8159085” 博客，请务必保留此出处http://8169085.blog.51cto.com/8159085/1696870
标签：java 算法
原文地址：http://8169085.blog.51cto.com/8159085/1696870
