C++ 詳解
線段樹 (分而治之)
https://www.tseng-school.com/2026/02/11/apcs/apcs202511/#%E7%AC%AC%E4%B8%89%E9%A1%8C-%E7%BF%BB%E4%BE%86%E8%A6%86%E5%8E%BB-ZeroJudge-r628