// 易错点4：栈空时要存-1（题目要求无更大值返回-1），而非直接存stack2.at(-1)（会得到undefined）
The US space agency has released a "pre-solicitation" for what is expected to be a hotly contested contract to develop a spacecraft to orbit Mars and relay communications from the red planet back to Earth.
，更多细节参见搜狗输入法2026
"NASA must standardize its approach, increase flight rate safely, and execute on the President’s national space policy. With credible competition from our greatest geopolitical adversary increasing by the day, we need to move faster, eliminate delays, and achieve our objectives," said Isaacman. "Standardizing vehicle configuration, increasing flight rate and progressing through objectives in a logical, phased approach, is how we achieved the near-impossible in 1969 and it is how we will do it again."
swap(&arr[i], &arr[j]);
第一百二十三条 受到罚款处罚的人应当自收到处罚决定书之日起十五日以内，到指定的银行或者通过电子支付系统缴纳罚款。但是，有下列情形之一的，人民警察可以当场收缴罚款：