设某物质有m个产地，n个销地，如果以 aij 表示由第 i 个产地销往第 j 个销地的数量，则这类物质的调运方案，可用一个数表表示如下-M has established a substance of origin, n sell, if in order to express AIJ i个origin from the first sold to the first j months of quantity sold, then the transport of such substances