Same Tree

题目：

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.

 

 

思路：和symmetric tree非常类似的递归解法

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