2018 ECNU AK ICPC/CCPC Typing Speed Contest

One,Two,Three,AK

Problem A

Solved by dreamcloud. 01:26:50(+1)

Problem B

Solved by oxx1108. 03:46:24(+7)

Problem C

Unsolved.

Problem D

Solved by oxx1108. 00:45:57(+)

Problem E

Solved by Xiejiadong. 03:52:04(+2)

题意：所有区间的众数出现的次数组成数列，求第$k$小的数。

题解：考虑二分答案，验证答案是否$\ge mid$。

checker 的写法是，枚举左端点，然后找到第一个出现次数达到$mid$的右边界，显然，这个边界右侧的都成立。用双指针法解决。

时间复杂度$o(nlogn)$。

Problem F

Solved by oxx1108. 00:33:40(+2)

Problem G

Unsolved.

Problem H

Unsolved.

Problem I

Solved by dreamcloud. 02:52:10(+)

Problem J

Unsolved.

Problem K

Unsolved.

Problem L

Solved by Xiejiadong. 02:23:14(+3)

题意：求$max_{a_i\ge a_j}(a_i mod a_j)$。

题解：