继承了上一篇文章中的树结构，增加了比较器。必须有明确的节点比较方法，否则无法进行基本操作。
package com.algorithm.tree;
import java.util.Comparator;
/**
* 左子树小于右子树的二叉查找树
*
* @author chao
*
* @param <T>
*/
public class BinarySeachTree<T> extends BinaryTree<T> {
private Comparator<T> comparator;
public BinarySeachTree(BinarySeachTree.BinaryTreeNode<T> root) {
this(root, null);
}
public BinarySeachTree(BinarySeachTree.BinaryTreeNode<T> root, Comparator<T> comparator) {
super(root);
this.comparator = comparator;
}
private int compare(BinarySeachTree.BinaryTreeNode<T> a, BinarySeachTree.BinaryTreeNode<T> b) {
if (comparator != null) {
return comparator.compare(a.element, b.element);
} else if (a.element instanceof Comparable && b.element instanceof Comparable) {
return ((Comparable) a.element).compareTo(b.element);
} else {
throw new RuntimeException("can't compare " + a.element.getClass());
}
}
} /**
* 从根节点插入一个新数据
*
* @param x
* @return
*/
public BinaryTreeNode<T> insert(BinaryTreeNode<T> x) {
return insert(root, x);
}
/**
* 从某一个节点插入新数据
*
* @param cur
* @param x
* @return
*/
protected BinaryTreeNode<T> insert(BinaryTreeNode<T> cur, BinaryTreeNode<T> x) {
if (cur == null) {
return x;
}
int compareresult = compare(cur, x);
if (compareresult < 0) {
cur.right = insert(cur.right, x);
} else if (compareresult > 0) {
cur.left = insert(cur.left, x);
}
return cur;
}/**
* 查找最小节点
*
* @return
*/
public BinaryTreeNode<T> findMin() {
return findMin(root);
}
/**
* 以node为根节点的最小节点
*
* @param node
* @return
*/
public BinaryTreeNode<T> findMin(BinaryTreeNode<T> node) {
if (node == null) {
return null;
} else if (node.left == null) {
return node;
}
return findMin(node.left);
}
/**
* 查找最大节点
*
* @return
*/
public BinaryTreeNode<T> findMax() {
return findMin(root);
}
/**
* 以node为根节点的最大节点
*
* @param node
* @return
*/
public BinaryTreeNode<T> findMax(BinaryTreeNode<T> node) {
if (node == null) {
return null;
} else if (node.right == null) {
return node;
}
return findMin(node.right);
}
/**
* 判断是否包含x
*
* @param x
* @return
*/
public boolean contains(BinaryTreeNode<T> x) {
return contains(root, x);
}
/**
* 以某个节点为根节点判断是否包含x
*
* @param cur
* @param x
* @return
*/
public boolean contains(BinaryTreeNode<T> cur, BinaryTreeNode<T> x) {
if (x == null || cur == null) {
return false;
}
int compareresult = compare(cur, x);
if (compareresult == 0) {
return true;
} else if (compareresult < 0) {
return contains(cur.right, x);
} else {
return contains(cur.left, x);
}
}/**
* 删除节点x
*
* @param x
* @return
*/
public BinaryTreeNode<T> remove(BinaryTreeNode<T> x) {
return remove(root, x);
}
/**
* 删除子树中的节点x
*
* @param cur
* @param x
* @return
*/
public BinaryTreeNode<T> remove(BinaryTreeNode<T> cur, BinaryTreeNode<T> x) {
if (cur == null || x == null) {
return cur;
}
int compareresult = compare(cur, x);
if (compareresult > 0) {
cur.left = remove(cur.left, x);
} else if (compareresult < 0) {
cur.right = remove(cur.right, x);
} else if (cur.left != null && cur.right != null) {
cur.right = remove(cur.right, findMin(cur.right));
} else {
cur = (cur.left == null) ? cur.right : cur.left;
}
return cur;
}欢迎扫描二维码，关注公众账号
原文：http://blog.csdn.net/robertcpp/article/details/51615905
