用贪心法解决背包问题：设有不同价值、不同重量的物品n件，求从这n件物品中选取一部分物品的方案，

使选中的物品的总重量不超过指定的限制重量，但选中物品的价值之和最大。-Knapsack problem with a greedy method to solve: with different values, different weights of items n pieces, find items from n items in the select part of the program, so that the total weight of the selected items does not exceed the specified weight limit, but selected and the maximum value of goods.