排序二叉树和红黑树

排序二叉树的Java实现

packag com.loonstudio;    /**  * 排序二叉树  * @author 骆昊  *  * @param <T> 泛型参数 树节点存储的元素的类型  */  public class BST<T extends Comparable<T>> {      private TreeNode root;  // 排序二叉树的根节点            /**      * 描述树节点结构的内部类      * @author 骆昊      *      */      private class TreeNode {          private T value;            // 树节点存储的元素          private TreeNode left, right;   // 指向左右孩子节点的引用                    public TreeNode(T value) {              this.value = value;          }      }            /**      * 返回树的节点个数      * @return      */      public int size() {          return size(root);      }            private int size(TreeNode x) {          if(x == null) {              return 0;          }          return size(x.left) + size(x.right) + 1;      }            /**      * 添加树节点      * @param t 待添加的元素      */      public void add(T t) {          root = add(root, t);      }            private TreeNode add(TreeNode x, T t) {          if(x == null) {              return new TreeNode(t); // 如果当前根节点为空 则创建新节点作为根节点          }          int cmp = t.compareTo(x.value);          if(cmp < 0) {              x.left = add(x.left, t);    // 小于根节点在左子树上添加          }          else if(cmp > 0) {              x.right = add(x.right, t);  // 大于根节点在右子树上添加          }          return x;      }            /**      * 删除树节点      * @param t 待删除的元素      */      public void delete(T t) {          root = delete(root, t);      }            private TreeNode delete(TreeNode x, T t) {          if(x == null) {              return null;          }          int cmp = t.compareTo(x.value);          if(cmp < 0) {              x.left = delete(x.left, t);          }          else if(cmp > 0) {              x.right = delete(x.right, t);          }          else {              if(x.right == null) {                  return x.left;  // 被删除的节点没有右子树则返回左子树替代被删除节点              }              if(x.left == null) {                  return x.right; // 被删除的节点没有左子树则返回右子树替代被删除节点              }              TreeNode temp = x;                x = min(x.right);   // 找到被删除节点右子树上最小节点(没有左子树)替代被删除节点              x.right = deleteMin(temp.right);    // 将被删除节点原来的右子树去掉最小节点后作为替代节点的右子树              x.left = temp.left;     // 将被删除节点原来的左子树作为替代节点的左子树          }          return x;      }            private TreeNode deleteMin(TreeNode x) {          if(x.left == null) {              return x.right;          }          x.left = deleteMin(x.left);          return x;      }            private TreeNode min(TreeNode x) {          if(x.left == null) {              return x;          }          return min(x.left);      }            /**      * 中序遍历(左-根-右): 排序二叉树的中序遍历可以得到一个有序序列      * @param v 元素访问器接口(实现元素访问操作的解耦合)      */      public void inOrder(Visitor<T> v) {          inOrder(root, v);      }            private void inOrder(TreeNode x, Visitor<T> v) {          if(x != null) {              inOrder(x.left, v);              v.visit(x.value);              inOrder(x.right, v);          }      }        /**      * 先序遍历(根-左-右)      * @param v 树元素访问器接口      */      public void preOrder(Visitor<T> v) {          preOrder(root, v);      }            private void preOrder(TreeNode x, Visitor<T> v) {          if(x != null) {              v.visit(x.value);              preOrder(x.left, v);              preOrder(x.right, v);          }      }  }  

元素访问器接口：

public interface Visitor<T> {        public void visit(T t);  } 

测试代码：

package com.loonstudio.test;    import com.accp.util.BST;  import com.accp.util.Visitor;    public class Test01 {        private static void printTree(BST<Integer> tree) {          System.out.println("先序: ");          tree.preOrder(new Visitor<Integer>() {                            @Override              public void visit(Integer t) {                  System.out.print(t + "\t");              }          });          System.out.println();          System.out.println("中序: ");          tree.inOrder(new Visitor<Integer>() {                            @Override              public void visit(Integer t) {                  System.out.print(t + "\t");              }          });          System.out.println();      }            public static void main(String[] args) {          Integer[] a = {54, 38, 76, 62, 38, 26, 40, 83, 50, 98, 80};                    BST<Integer> tree = new BST<Integer>();          for(int i = 0; i < a.length; i++) {              tree.add(a[i]);          }                    printTree(tree);                    tree.delete(54);                    printTree(tree);                    tree.delete(38);                    printTree(tree);                                    }  }