C Optimal Strategy
题目链接Ena and Mizuki are playing a game.There are n items in front of them, numbered from 1 to n. The value of the i-th item is ai. Ena and Mizuki take turns to move, while Ena moves first. In a move, t
K Search For Mafuyu
题目链接Mafuyu has hidden in Sekai, and Kanade is searching for her.In Sekai, there is nothing but a lot of rooms. There are n rooms in Sekai, numbered from 1 to n. Besides, n−1 pairs of rooms are directl