背包问题是用贪心算法得到最优解得一个典型问题。背包问题具有最优子结构性质首先通过快速排序算法对物品按照单价从大到小排序，然后进行贪心选择。-Knapsack problem is a greedy algorithm with the optimal solution may be a typical problem. Knapsack problem with the nature of the optimal sub-structure, first of all, quick sort algorithm to sort items in accordance with the smallest unit, and then choose to greed.