ABC142
A.Odds of Oddness
Time:\(1:00\)
Dif:\(\color{Gray}{28}\)
Skip.
B.Roller Coaster
Time:\(2:38\)
Dif:\(\color{Gray}{33}\)
Skip.
C.Go to School
Time:\(4:41\)
Dif:\(\color{Gray}{118}\)
Skip.
D.Disjoint Set of Common Divisors
Time:\(8:52\)
Dif:\(\color{Green}{827}\)
Description
给定两个数 \(a,b\),在他们的公约数集合中选择尽可能多的数使他们两两互质。
Solution
答案就是 \(a,b\) 素公约数的个数。
E.Get Everything
Time:\(15:34\)
Dif:\(\color{Turquoise}{1397}\)
Description
有 \(N\) 个上锁的宝箱,编号为 \(1\) 到 \(N\)。有 \(M\) 把钥匙,第 \(i\) 把钥匙的代价为 \(a_i\),解锁箱子 \(c_{i,1},c_{i,2},c_{i,3}\ldots c_{i,b_i}\)。问打开所有的箱子的最小代价。
\(1\leq N\leq12,1\leq M\leq1000,1\leq a_i\leq10^5,1\leq b_i\leq N\)
Solution
状压每把钥匙能开的锁,然后做 01 背包即可。方程: $$f_{w_i|j}=\min f_{w_i|j},f_{j}+v_i $$