LeetCode: same-tree

Topic description

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.

Check whether two binary trees are equal, return Boolean

The program implementation is very simple, but pay attention to the order of judgment, first judge whether the binary tree has been traversed at the same time, and then go to AND.

p == null && q == null

public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
       if (p == null && q == null)
            return true;
        if(p==null||q==null){
            return false;
        }
        
        if (p.val != q.val)
            return false;
  
        return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
    }
}