暴力怎么做？考虑我们把前缀弄成全 $\geq 0$，后缀弄成全 $\geq 0$ 就合法了，然后这个过程显然是互不影响的，直接模拟可以做到 $O(n^2\log n)$。
考虑维护哪些数在这个匹配里，每次只需要找到可以被替换的位置即可。
于是可以做到 $O(n\log n)$。
QOJ.ac
QOJ
As we are currently experiencing an overwhelming number of web requests for fetching user submissions, we have temporarily disabled the full submissions list. You must now be logged in to view submissions.
Discussion #122 for Problem #7973. 括号
Type: Editorial
Status: Open
Posted by: dXqwq
Posted at: 2025-12-12 23:11:37
Last updated: 2025-12-12 23:11:42
题解
Comments
No comments yet.