2017-2018 ACM-ICPC East Central North America Regional Contest (ECNA 2017)
Problem A
Solved by ultmaster. 04:33 (+)
Problem B
Solved by kblack. 03:18 (+1)
题意:给定 $N$ 个圆,求包围图形的最小周长。
题解:类似凸包的 $O(nh)$ 算法,每次寻找包围图形上下一个点,通过角度的变化计算弧线的长度,注意处理圆包含等情况。
Problem C
Solved by zerol. 00:09 (+)
温暖的签到。
Problem D
Solved by kblack. 00:21 (+)
温暖的签到。
Problem E
Solved by ultmaster. 01:09 (+3)
Problem F
Solved by kblack. 01:04 (+)
温暖的树形签到。
Problem G
Solved by kblack. 01:31 (+)
温暖的 DP 签到。
Problem H
Solved by zerol. 00:17 (+)
温暖的签到。
Problem I
Solved by ultmaster. 02:17 (+)
Problem J
Solved by zerol. 01:22 (+)
题意:给 10 个装置,每个装置都有人使用休息循环。问有个人装置一个个用过来使用休息循环共三轮,如果发现别人在用或刚开始用就要等待,反过来也要等待,问完成时间。
题解:模拟。