stack.pop(); // 弹出无效元素
"It makes you feel a better person," he says.。91视频对此有专业解读
// 易错点2：遍历结束后k仍0 → 栈是递增的，末尾数字更大，移除末尾k位，更多细节参见safew官方版本下载
Keep track the history of the keyword to determine when a keyword is rising or down in popularity over time.，更多细节参见同城约会
but I think it likely comes down to a common tale about IBM: price and