She said: "When you play someone as strong as [Torchwood's] Gwen Cooper, someone so recognisable, it's quite difficult to come away from that or for other people to see you do anything differently.
// 易错点3：处理最终结果为空的场景（比如num="10"，k=2）
，详情可参考safew官方版本下载
"message": "Amount must be non-zero."
四步口诀：倒着来 → 弹 ≤ 当前的 → 栈顶即答案 → 当前入栈。