Java实现二叉搜索树

二叉搜索树

我们可以用二叉搜索树中的插入操作构建一棵二叉搜索树

二叉搜索树的伪代码：

Java实现：

public class BSTree {
    Node<Integer> root = new Node<Integer>();
    public BSTree(){
        this.root = null;
    }
    //插入
public Node<Integer> insert (int key) {
    Node<Integer> newNode = new Node<>(key);
    Node<Integer> current = root;
    Node<Integer> parent  = null;
    if (current == null) {
        root = newNode;
        return newNode;
    }
    while (true) {
        parent = current;
        if (key < current.data) {
            current = current.left;
            if (current == null) {
                parent.left = newNode;
                return newNode;
            }
        } else {
            current = current.right;
            if (current == null) {
                parent.right = newNode;
                return newNode;
            }
        }
    }
}


    //前序遍历
    public void PreOrder(Node node) {
        if (node != null) {
            System.out.print(node.data + "  ");
            PreOrder(node.left);
            PreOrder(node.right);
        }
    }

}

我们实现一棵这样的BST

测试类：

public class BSTreeTest {
    public static void main(String[] args) {
        BSTree tree =new BSTree();
        tree.insert(30);
        tree.insert(15);
        tree.insert(41);
        tree.insert(35);
        tree.insert(50);
        tree.PreOrder(tree.root);
    }
}

结果：

30  15  41  35  30  50