2018-2019 ACM-ICPC, Asia Nakhon Pathom Regional Contest
Problem A
Unsolved.
Problem B
Unsolved. (-2)
Problem C
Solved by Xiejiadong. 00:24 (+)
简单的 dp 签到。
Problem D
Solved by Xiejiadong. 00:08 (+)
题意:要使得每个地点的 $10$ km 范围内有一个公交车站,求最少需要的公交车真。
题解:贪心。对地点的距离排序以后,每一次公交车站一定放在一个没有公交车站的最靠前的地点之后 $10$ km 处。扫一遍即可。
Problem E
Unsolved. (-1)
Problem F
Solved by Kilo_5723 && Xiejiadong. 04:16 (+1)
题意:求杨辉三角中前 $n$ 行中能被 $7$ 整除的数的个数。
题解:杨辉三角模素数的余数是分形,用分形的规律做。
Problem G
Solved Weaver_zhu && Kilo_5723. 01:02 (+)
Problem H
Solved by Kilo_5723. 01:42 (+)
Problem I
Unsolved.
Problem J
Solved by Kilo_5723. 00:20 (+)
Problem K
Solved by Xiejiadong && Weaver_zhu. 04:21 (+)
题意:每个数有出现的一个时间区间,每次询问一个时间点的第 $k$ 大数。
题解:会有重复的数,没法 pb_ds 。
对时间离散以后,用平衡树维护即可。
Problem L
Solved by Weaver_zhu. 00:53 (+)