[BZOJ2228] [Zjoi2011] Gift (gift) (mess up???) ) __orz

First consider the case of long and wide equality.
See the size of the cuboid to be chosen is AXAXB axaxb a\times a\times B,
You may consider preprocessing the first for each (I,J,K) (I, J, K) (I,j,k), in K K K-layer, with (I,J) (I, J) (I,J) as the largest full N square in the lower right corner edges s (i,j,k) s (i, J, K ) s (i,j,k). This can be pretreated by the suspension method O (PQR) O (P q r) O (PQR).
Then enumerate 1≤i≤p,1≤j≤q 1≤i≤p, 1≤j≤q 1\le i\le p,1\le j\le Q, and set the x x x coordinate right boundary of the sub cuboid as I i i, y y y coordinate right boundary is J J J.
At this point, if the z z coordinate range is [x,y] (1≤X,Y≤R) [X, Y] (1≤x, y≤r) [X,y] (1\le x,y\le R), then the maximum 4ab 4 a B 4ab under such a restriction is:
4 (y−x+1) Mink=xys (i,j,k) 4 (y−x + 1) min