跃迁引擎启动

rank solved A B C D E F G H I J K L M
74 7 O . . ! . . O O O O O . O

Solved by wb.

Solved by wb.

Solved by wb.

Solved by XLor.

Solved by XLor.

dfs 建主席树，LCA 差分

Solved by XLor.

Solved by XLor.