2. 环境准备（macOS 本地）
* 时间O(n) 空间O(n)（理论最优，无冗余计算）
，更多细节参见新收录的资料
德黑蘭或許期望這些政府施壓美國限制或停止行動——但這是危險的賭注。如果進一步擴大攻擊，可能反而讓這些國家更加敵視伊朗，並更堅定地站到美以陣營一邊。。关于这个话题，PDF资料提供了深入分析
"This bill expands the current law protecting our kids online to ensure companies cannot collect personal information from anyone under the age of 17," Senate Democratic Leader Chuck Schumer (D-NY) said in a statement about the latest result. "This is a big step forward for protecting our kids. We hope the House can join us. They haven’t thus far."