2025-01-19 二叉树的遍历搜索

src/dataANDcalc/java/tree/BinaryTreeIterator.java

@@ -1,6 +1,6 @@
 package tree;
 
-public class TreeIterator {
+public class BinaryTreeIterator {
 
     private TreeNode root;
 
@@ -108,7 +108,7 @@ public class TreeIterator {
 
     public static void main(String[] args) {
         int[] arr = {7, 3, 10, 12, 5, 1, 9};
-        TreeIterator treeIterator = new TreeIterator();
+        BinaryTreeIterator treeIterator = new BinaryTreeIterator();
         treeIterator.transTree(arr);
         System.out.println("前序遍历:");
         treeIterator.forwardIterator(treeIterator.root);

src/dataANDcalc/java/tree/BinaryTreeSearch.java

@@ -0,0 +1,157 @@
+package tree;
+
+public class BinaryTreeSearch {
+
+    private TreeNode root;
+
+    private void transTree(int[] arr){
+        for (int i = 0; i < arr.length; i++) {
+            TreeNode treeNode = new TreeNode(arr[i]);
+            addNode(root, treeNode);
+        }
+    }
+
+    private void addNode(TreeNode tempNode, TreeNode treeNode){
+        if(root == null){
+            root = treeNode;
+            return;
+        }
+
+        if(treeNode.node<tempNode.node){
+            if (tempNode.left == null){
+                tempNode.left = treeNode;
+            } else {
+                addNode(tempNode.left, treeNode);
+            }
+        }
+
+        if(treeNode.node>tempNode.node){
+            if (tempNode.right == null){
+                tempNode.right = treeNode;
+            } else {
+                addNode(tempNode.right, treeNode);
+            }
+        }
+    }
+
+    private TreeNode forwardSearch(TreeNode treeNode, int node){
+        TreeNode resultNode = null;
+        if(treeNode == null){
+            System.out.println("当前节点为空");
+            return null;
+        }
+
+        if(treeNode.node == node){
+            System.out.println("已找到treeNode:"+ treeNode.toString());
+            resultNode = treeNode;
+            return resultNode;
+        }
+        System.out.println("当前treeNode为："+ treeNode.toString());
+
+        if (treeNode.left != null){
+            resultNode = forwardSearch(treeNode.left, node);
+        }
+
+        if(resultNode != null){
+            return resultNode;
+        }
+
+        if (treeNode.right!= null){
+            resultNode = forwardSearch(treeNode.right, node);
+        }
+        return resultNode;
+    }
+
+    private TreeNode middleSearch(TreeNode treeNode, int node){
+        TreeNode resultNode = null;
+        if(treeNode == null){
+            System.out.println("当前节点为空");
+            return resultNode;
+        }
+
+        if (treeNode.left!= null){
+            resultNode = middleSearch(treeNode.left, node);
+        }
+
+        if(resultNode!= null){
+            return resultNode;
+        }
+
+        if(treeNode.node == node){
+            System.out.println("已找到treeNode:"+ treeNode.toString());
+            resultNode = treeNode;
+            return resultNode;
+        }
+        System.out.println("当前treeNode为："+ treeNode.toString());
+
+        if (treeNode.right!= null){
+            resultNode = middleSearch(treeNode.right, node);
+        }
+        return resultNode;
+    }
+
+    private TreeNode behindSearch(TreeNode treeNode, int node){
+        TreeNode resultNode = null;
+        if(treeNode == null){
+            System.out.println("当前节点为空");
+            return resultNode;
+        }
+
+        if (treeNode.left!= null){
+            resultNode = behindSearch(treeNode.left, node);
+        }
+
+        if(resultNode != null){
+            return resultNode;
+        }
+
+        if (treeNode.right!= null){
+            resultNode = behindSearch(treeNode.right, node);
+        }
+
+        if(resultNode != null){
+            return resultNode;
+        }
+
+        if(treeNode.node == node){
+            System.out.println("已找到treeNode:"+ treeNode.toString());
+            resultNode = treeNode;
+            return resultNode;
+        }
+        System.out.println("当前treeNode为："+ treeNode.toString());
+        return resultNode;
+    }
+
+    public static class TreeNode{
+        private int node;
+
+        private TreeNode left;
+
+        private TreeNode right;
+
+        public TreeNode(int node) {
+            this.node = node;
+        }
+
+        @Override
+        public String toString() {
+            return "TreeNode{" +
+                    "node=" + node +
+                    ", left=" + (left == null ? "null" : left.node) +
+                    ", right=" + (right == null ? "null" : right.node) +
+                    '}';
+        }
+    }
+
+    public static void main(String[] args) {
+        int[] arr = {7, 3, 10, 12, 5, 1, 9};
+        BinaryTreeSearch treeSearch = new BinaryTreeSearch();
+        treeSearch.transTree(arr);
+        System.out.println("前序遍历:");
+        treeSearch.forwardSearch(treeSearch.root, 5);
+        System.out.println("中序遍历:");
+        treeSearch.middleSearch(treeSearch.root, 5);
+        System.out.println("后序遍历:");
+        treeSearch.behindSearch(treeSearch.root, 5);
+    }
+}