P2905 [USACO08OPEN]农场危机Crisis on the Farm 发现总步数$k<=30$,考虑用$k$瞎搞 设$f[u][i][j]$表示已经吹$u$次哨,全体奶牛向右走$i$步,向上走$j$步的最优解 预处理$g[i][j]$表示全体奶牛向右走$i$步,向上走$j$步可以救几只奶牛 显然$f[u][i][j]=max(f[u+1][i+1][j],f[u+1][i-1][j],f[u+1][i][j+1],f[u+1][i][j-1])+g[i][j]$ 把方向按字典序,逆…
传送门 DP 设 f [ i ] [ j ] [ k ] 表示已经走了 i 步,向上走了 j 步,向右走了 k 步时能拯救的最多奶牛数(j,k可以为负,表示反向) 设 g [ i ] [ j ] 表示牛向上走 i 步,向右走 j 步后有多少奶牛恰好在草堆上(同样 i , j 可负) 那么 f [ i ] [ j ] [ k ] = max( f [ i-1 ] [ j -1 ] [ k ] , f [ i-1 ] [ j ] [ k-1 ] , f [ i-1 ] [ j+1 ] [ k ] ,…
P2908 [USACO08OPEN]文字的力量Word Power 题目描述 Farmer John wants to evaluate the quality of the names of his N (1 <= N <= 1000) cows. Each name is a string with no more than 1000 characters, all of which are non-blank. He has created a set of M (1 <= M…
P2910 [USACO08OPEN]寻宝之路Clear And Present Danger 题目描述 Farmer John is on a boat seeking fabled treasure on one of the N (1 <= N <= 100) islands conveniently labeled 1..N in the Cowribbean Sea. The treasure map tells him that he must travel through a c…
P3079 [USACO13MAR]农场的画Farm Painting 题目描述 After several harsh winters, Farmer John has decided it is time to re-paint his farm. The farm consists of N fenced enclosures (1 <= N <= 50,000), each of which can be described by a rectangle in the 2D plane…
P2908 [USACO08OPEN]文字的力量Word Power 题目描述 Farmer John wants to evaluate the quality of the names of his N (1 <= N <= 1000) cows. Each name is a string with no more than 1000 characters, all of which are non-blank. He has created a set of M (1 <= M…
