100 Same Tree

原题链接：Same Tree

class Solution:
    # @param {TreeNode} p
    # @param {TreeNode} q
    # @return {boolean}
    def isSameTree(self, p, q):
        if p is None and q is None:
            return True
        elif p is None or q is None:
            return False
        else:
            if p.val == q.val:
                return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)
            return False