二叉树右视图

def solve(____):
    from collections import deque
    if not root:
        return []
    result, q = [], deque(____)
    while q:
        size = len(____)
        for i in range(____):
            node = q.popleft()
            if i == size - ____:
                result.append(____)
            if node.left:
                q.append(____)
            if node.right:
                q.append(____)
    return result