Codeforces Round #791 (Div. 2)(Codeforces Round #791 (Div. 2))

AB签得比较顺利,A题一个类似线性规划的问题,对比下解法我做得还是太复杂了,印象中这种类似的point在一次div2C里出现了没搞出来,那个线性规划好像复杂很多

C题又卡了,这次是真服了,题目都读错了在那瞎想了一个多小时,把or以为成and,最后读懂之后树状数组维护还是比较简单的,不过应该有更好的解法

D题就剩10min了,应该是那种图上的dp,或者说记忆化搜索吧,做得比较少,也没什么信心能做出来。。。

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The signing of AB was relatively smooth. Question a is a problem similar to linear programming. Compared with the solution, I still made it too complicated. In my impression, this similar point appeared in div2c, but it didn’t come out. That linear programming seems to be much more complicated

The C question is stuck again. This time it’s really convinced. The questions are read wrong. I thought about it for more than an hour and thought or as and. Finally, after reading it, the maintenance of the tree array is relatively simple, but there should be a better solution

There are only 10 minutes left for question D. it should be the DP on the graph, or memory search. It has been done less and has little confidence to do it…