背包问题：背包问题的贪心算法要求按照单位容量效益值的高低的量度标准进行排序，然后再分级选取，

求得最优解。实现此算法，物品个数，每件物品的效益值，容量值，背包容量值都由键盘输入；

输出结果要有每件物品的详细信息。-Knapsack problem: the greedy algorithm knapsack problem required the capacity benefits in accordance with unit value measure of the level of sort, and then select the grade, get the optimal solution. Implement this algorithm, the number of items, each item of the effectiveness of value, capacity value, pack capacity value by the keyboard input　the output have the details of each item.