说明：  1．在选择装入背包的物品时，对每种物品I只有两种选择，即装入背包或不装入背包。不能将物品I装入背包多次，也不能只装入部分的物品I。 2．物品的种数，重量、价值，背包的容量要求输入； 3．算法中加入剪枝函数（对重量已经超过限制重量的子树不搜索）；
(1. In the selection of the items into the backpack, for each of the items I have only two choices, that is loaded or not loaded backpack backpack. Items should not be many times I load backpack can not only part of the goods loaded I. 2. Number of species items, weight, value, capacity backpack for the importation 3. Algorithm to add pruning function (of weight over the weight limit does not search sub-tree) )