原题下载 USACO2015OPEN-S3 答案 (Analysis by Nick Wu) Start by sorting the patches of the grass in increasing order of quality. Let?f(i)?be the maximum energy that we can accumulate if we end at pat...
原题下载 USACO2015OPEN-S2 答案 (Analysis by Nick Wu). If we pick a bale that we want to add hay to, then we can guarantee that Bessie cannot break through that bale. Therefore, once we have picked ...
原题下载 USACO2015OPEN-S1 答案 (Analysis by Nick Wu) There are?5007?different combinations to check, which is far too many. However, just like with the bronze version of this problem, where we were...
原题下载 USACO2015OPEN-B4 答案 (Analysis by Nick Wu) Our first thought is to try all possible paths that Bessie can take. For small?N, this works out well, but it turns out that for a grid of size?...
原题下载 USACO2015OPEN-B2 答案 (Analysis by Nick Wu) In a pure brute-force solution, we would try every possible combination of assignments of variables to values. There are 7 variables, with at mo...
原题下载 USACO2015OPEN-B3 答案 (Analysis by Nick Wu) The?NN?hay bales define?N?1N?1?intervals that Bessie can be inside. Let's consider answering for a given interval, whether Bessie can escape if ...
原题下载 USACO2015OPEN-B1 答案 (Analysis by Nick Wu) There are too many substitution ciphers for us to check every single one and see which one gives the maximum number of MOOs. However, if we only...
原题下载 USACO2015FEB-G3 答案 (Analysis by Richard Peng) This problem is a dynamic (insertion of points) version of?"a highway and seven dwarfs" from CEOI 2002. It asks to support a point set (the ...
原题下载 USACO2015FEB-G2 答案 (Analysis by Mark Gordon) This problem asks us to repeatedly delete the first occurrence of any string?TiTi?from a larger string?S?until no string?Ti?appears in?S. Unf...
