代码如下:
package BSTree;import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;public class BSTree {private class TreeNode{int data;TreeNode left;TreeNode right;public TreeNode(int e){data = e;left = null;right = null;}}private TreeNode BSTreeRoot;public BSTree(){BSTreeRoot=null;}public TreeNode findElem(int e,TreeNode root){if (root==null) return null;if (e > root.data){return findElem(e,root.right);}else if (e < root.data){return findElem(e,root.left);}else{return root;}}public TreeNode findMin(TreeNode root){if (root==null) return null;else if (root.left==null){return root;}else return findMin(root.left);}public TreeNode findMax(TreeNode root){if (root==null) return null;else if (root.right==null){return root;}else return findMax(root.left);}public TreeNode insertTree(int e,TreeNode root){if (root==null){root = new TreeNode(e);root.left = root.right = null;}else{if (e > root.data){root.right = insertTree(e,root.right);}else if (e < root.data){root.left = insertTree(e,root.left);}}return root;}public TreeNode deleteTree(int e,TreeNode root){if (root==null){System.out.println("The elem is found");return null;}else if (e > root.data){root.right = deleteTree(e,root.right);}else if (e < root.data){root.left = deleteTree(e,root.left);}else{if (root.left!=null && root.right!=null){TreeNode tmp = findMin(root.right);root.data = tmp.data;root.right = deleteTree(root.data,root.right);}else{if (root.left==null){root = root.right;}else if (root.right==null){root = root.left;}}}return root;}public boolean createTree(int n){Scanner sc = new Scanner(System.in);for (int i = 0;i<n;i++){int val = sc.nextInt();BSTreeRoot = insertTree(val,BSTreeRoot);}return true;}public void levelOrder(){ArrayList<Integer> arrays = new ArrayList<>();if (BSTreeRoot==null){System.out.println(arrays);return ;}Queue<TreeNode> q = new LinkedList<>();q.add(BSTreeRoot);while(!q.isEmpty()){TreeNode t = q.poll();arrays.add(t.data);if (t.left!=null) q.add(t.left);if (t.right!=null) q.add(t.right);}System.out.println(arrays);return ;}}测试类如下:
package BSTree;public class TestBSTree {public static void main(String[] args){BSTree bt = new BSTree();bt.createTree(5);bt.levelOrder();}
}时间递归过程，将该树每个节点关键字输出（算法导论第十章10.4-2）)
时间非递归过程，将该树每个节点关键字输出，可以使用一个栈作为辅助数据结构（算法导论第十章10.4-3）)
)
)
时间的非递归的过程，将该树每个结点的关键字输出（算法导论第三版第十章10.4-5）)
)
)
)