jcreator下写的背包问题，适合JAVA入门。给定背包的容量，在输入的物品中，求出符合条件的解，如果不存在解，则输出不存在-jcreator written under the knapsack problem, for JAVA entry. Given knapsack capacity, in input items, find qualified solution, if there is no solution, the output does not exist