判断两棵树是否相同

微信图片_20191221183656.jpg

class Solution:
    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        if p is None and q is None:
            return True
        if p is None:
            return False
        if q is None:
            return False
        
        if p.val != q.val:
            return False
        else:
            left = self.isSameTree(p.left, q.left)
            right = self.isSameTree(p.right, q.right)
            return left and right