2018-2019 Russia Open High School Programming Contest

Problem A

Solved by kblack. 00:17 (+1)

Problem B

Solved by ultmaster. 01:09 (+)

Problem C

Solved by ultmaster. 03:57 (+1)

Problem D

Solved by zerol. 01:18 (+)

Problem E

Solved by kblack. 02:11 (+)

Problem F

Upsolved by ultmaster.

题意：有 $n$ 个数让你猜，每次询问三个下标，回答你这三个下标上的数的最大值和最小值的和。要求在 $4n$ 次内猜出来。

题解（无脑）：考虑 $n=5$ 的做法，总共能拿到 10 份信息，暴力枚举顺序后，列出方程，用高斯消元解出来，判合法性。然后 5 个 5 个做下去就好了。

全真模拟现场赛意识模糊写不了题的症状。

Problem I

Solved by zerol. 00:47 (+1)

Problem K

Solved by kblack. 01:28 (+)

Problem L

Solved by zerol. 02:22 (+)

Problem M

Solved by kblack. 00:04 (+)