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[leetcode]same tree

admin 11月 12, 2020 0

题目描述

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

代码


 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class  {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        //都为空返回true
        if(p == null && q == null) return true;
        //if((p == null && q != null) || (p != null && q == null)) return false;
        //只有一个为null，返回false
        if(p == null || q == null ) return false;
        //递归调用   
        return p.val==q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }
}