背包问题(Knapsack problem)是一种组合优化的NP完全问题。给定一组物品，每种物品都有自己的重量和价格，在限定的总重量内，我们如何选择，才能使得物品的总价格最高。(Knapsack problem is a NP-complete problem of normaloptimization. Each item has its own weight and price. In the limited total weight, how can we choose to make the total price of the item the highest?)