零件切割问题

给定一块宽度为W的矩形板，矩形板的高度不受限制。现需要从板上分别切割出n个高度为hi，宽度为wi的矩形零件。切割的规则是零件的高度方向与矩形板的高度方向保持一致。问如何切割使得所使用的矩形板的高度h最小？

-parts cutting issue for a fixed width of the rectangular plate W, the height of rectangular plate unrestricted. Need from the board is cutting out respectively n height of the hi, wi width of the rectangular parts. Cutting parts to the rules of the height of the rectangular plate with a high degree of consistent direction. Asked how cutting makes use of the rectangular plate height h minimum?