1. 分解：将数组递归分成两半，直到只剩1个元素
其他更新细节参考 MacRumors 和 AppleInsider 报道整理如下：
。heLLoword翻译官方下载对此有专业解读
// 边界处理：nums1为空时直接返回空数组（避免后续无效计算）
"It's not a cure, but because I got a good remission, that hopefully means that I'll keep the cancer at bay for a good long time."