力扣——相同的树

Posted 2021-12-04 七元K

相同的树

给你两棵二叉树的根节点 p 和 q ，编写一个函数来检验这两棵树是否相同。

如果两个树在结构上相同，并且节点具有相同的值，则认为它们是相同的。

示例 1：

输入：p = [1,2,3], q = [1,2,3]
输出：true

示例 2：

输入：p = [1,2], q = [1,null,2]
输出：false

示例 3：

输入：p = [1,2,1], q = [1,1,2]
输出：false

提示：

两棵树上的节点数目都在范围 [0, 100] 内
-104 <= Node.val <= 104

---

/**
    * Definition for a binary tree node.
    * public class TreeNode {
    *     int val;
    *     TreeNode left;
    *     TreeNode right;
    *     TreeNode() {}
    *     TreeNode(int val) { this.val = val; }
    *     TreeNode(int val, TreeNode left, TreeNode right) {
    *         this.val = val;
    *         this.left = left;
    *         this.right = right;
    *     }
    * }
 */
class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
 if(p==null&&q==null){
            return true;
        }else if(p==null||q==null){
            return false;
        }else if (p.val!=q.val){
            return false;
        }else{
            return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
        }
    }
}

---

    package com.kk;
    
    public class IsSameTree {
    
        public boolean isSameTree(TreeNode p, TreeNode q) {
            if(p==null&&q==null){
                return true;
            }else if(p==null||q==null){
                return false;
            }else if (p.val!=q.val){
                return false;
            }else{
                return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
            }
        }
    
    
    
        public class TreeNode {
            int val;
            TreeNode left;
            TreeNode right;
            TreeNode() {}
            TreeNode(int val) { this.val = val; }
            TreeNode(int val, TreeNode left, TreeNode right) {
                this.val = val;
                this.left = left;
                this.right = right;
            }
        }
    }