采用多目标粒子群算法求解多目标背包问题 问题：假设存在五类物品，每类物品又包含四种具体物品，要求从五类物品中分别选择一种放入背包，使得背包总价值最大，总体积最小，总质量不超过92kg(The problem is solved by multi objective particle swarm optimization algorithm, multi-objective knapsack problem: suppose there are five categories of goods,