Discard old data: evict what's already buffered to make room
// 解释：第一个有效数字不能是0，栈空时存0无意义，直接跳过，详情可参考safew官方版本下载
。业内人士推荐爱思助手下载最新版本作为进阶阅读
"Instead of pulling the oil and gas up from the ground, we're going to inject the CO2 into the ground instead," he says.，详情可参考51吃瓜
move this to the scavanged list:
Check how all the judges voted | Our methodology