class 树节点中的构造函数树节点无法应用于 java 中的给定类型?
Constructor treenode in class treenode cannot be applied to given types in java?
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public TreeNode buildTree(int[] preorder, int[] inorder) {
TreeNode ans = new TreeNode();
if(preorder.length == 0) return ans;
// do something
return ans;
}
我想初始化一个空的TreeNode
,但是遇到如下错误:
constructor treenode in class treenode cannot be applied to given types
如何解决这个错误?
在定义带参数的构造函数时,必须显式定义默认构造函数。
TreeNode() {
//initialize value
}
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public TreeNode buildTree(int[] preorder, int[] inorder) {
TreeNode ans = new TreeNode();
if(preorder.length == 0) return ans;
// do something
return ans;
}
我想初始化一个空的TreeNode
,但是遇到如下错误:
constructor treenode in class treenode cannot be applied to given types
如何解决这个错误?
在定义带参数的构造函数时,必须显式定义默认构造函数。
TreeNode() {
//initialize value
}