
ZOJ Problem Set  1321
Two points A(x1, y1, z1) and B(x2, y2, z2) are placed on the surface of parallelepiped P = {(x, y, z): 0 <= x <= L, 0 <= y <= W, 0 <= z <= H} with L*W*H dimensions (see figure). These two points can be linked with various curves lying on the surface of P. You are to find out the square of the shortest curve length. Parallelepiped dimensions L, W, H and coordinates of the points are integers, 0 <= L,W,H <= 1000.
5 5 2 3 1 2 3 5 0
Source: Northeastern Europe 1996 