最小重量机器设计问题：设某一机器由N个部件组成，每一个部件都可以从M个不同的供应商处购得。设wij是从供应商j处购得部件i的重量，cij是相应的价格。试设计一个算法-Minimum weight design problems in the machine: a machine set up by the N-components, each component can be different from the M vendors. Wij for j from supplier i purc