2013-2014 Petrozavodsk Winter Training Camp, Saratov SU Contest
Problem A
Unsolved.
Problem B
Solved by kblack, translated by zerol. 03:51 (+)
题意:双倍汉诺塔,规定最后同大小饼的顺序。
题解:正常移动一堆需要两倍正常汉诺塔的时间,而且会导致移动的最下两个饼反向,多消耗一些操作可以修正,但小一号的饼会反向,往上逐层处理,注意特判最顶上的情况。
zerol: 没我啥事,就打了个暴力。
Problem C
Solved by ultmaster. 01:16 (+)
Problem D
Unsolved.
Problem E
Solved by zerol. 00:32 (+)
题意:给若干个字符串,要求两两配对,使得每一对的最长公共前缀的长度和最大。
题解:全部插入一棵 trie,如果某个结点有超过两个字符串,就两两一对用掉,如果剩下一个的话就丢给父节点。
Problem F
Solved by kblack. 01:33 (+)
题意:一堆点,可以对 $x = y$ 对称变换,要求变换后按横坐标是不降且纵坐标不升。
题解:先全部折到对称轴上方,然后从左上找一条符合要求的序列,剩下的再找一条,如果还剩那就完蛋了,两条的尾巴判断一下,如果两个可以共存那就构造好了,否则本来也是要完蛋的。
Problem G
Unsolved.
Problem H
Unsolved.
Problem I
Unsolved.
Problem J
Solved by kblack. 00:54 (+)
温暖的枚举签到。
Problem K
Solved by ultmaster. 03:59 (+1)