在不超出预算的情况下，选择每种类型的具有最高价值的物品

Question

给出以下项目列表，预算B和项目类型列表（T1，T2，T3 ... TN），从每种类型中选择1个提供最大价值（最昂贵）而又不超出预算的项目

[
  {
    "id": "1",
    "types": "T1",
    "price": 1000,
  },
  {
    "id": "2",
    "types": "T2",
    "price": 109292,
  },
  {
    "id": "3",
    "types": "T3",
    "price": 7228,
  },
  {
    "id": "4",
    "types": "T4",
    "price": 1000,
  },
]

研究了背包问题，不确定是否是NP完全问题。

Answer 1

只需使用filter查找不超过预算的所有项目，然后按sort降序排列并采用第一个元素：

const array = [{
    "id": "1",
    "types": "T1",
    "price": 1000,
  },
  {
    "id": "2",
    "types": "T2",
    "price": 109292,
  },
  {
    "id": "3",
    "types": "T3",
    "price": 7228,
  },
  {
    "id": "4",
    "types": "T4",
    "price": 1000,
  },
];

const budget = 9000;

var budgetMatch = array.filter(({ price }) => price <= budget);
budgetMatch.sort(({ price: a}, { price: b}) => b - a);

var highestPrice = budgetMatch[0];

console.log(highestPrice);