* 核心思路：单调递增栈 + 控制删除位数（k0），优先移除高位大数，保证剩余数字最小
"I'm pretty comfortable with the aspiration to be in a unique special relationship as long as we remember it needs to be created," he says.
。关于这个话题，服务器推荐提供了深入分析
swap(&arr[low], &arr[j]);
FT Edit: Access on iOS and web