动态规划（背包问题）

public class BagProblem {
 
 public static void  main(String[] arg){
  //背包承受的重量
  final int MAX_WEIGHT = 8;
  final int MIN_WEIGHT = 1;
  //value决定当前的价值
  int[] value = new int[MAX_WEIGHT+1];
  //item记录选的是谁
  int[] item = new int[MAX_WEIGHT+1];
  FruitInBag[] FruitInBags = {
     new FruitInBag("李子",4,4500),new FruitInBag("苹果",5,5700),
     new FruitInBag("橘子",2,2250),new FruitInBag("草莓",1,1100),new FruitInBag("甜瓜",6,6700)};
  for(int i = 0;i<FruitInBags.length;i++){
   
   //j为当前背包的重量
   for(int j = FruitInBags[i].getWeight();j<=MAX_WEIGHT;j++){
    //剩余空间
    int p = j - FruitInBags[i].getWeight();
    int newValue = FruitInBags[i].getPrice()+value[p];
    if(newValue >value[j]){
     value[j] = newValue;
     item[j] = i;
    }
   }
  }
  for(int i:item){
   System.out.print(i);
  }
 }
}
class FruitInBag {
 private String name;
 private int weight;
 private int price;
 public FruitInBag(String name,int weight,int price){
  this.name = name;
  this.price = price;
  this.weight = weight;
 }
 
 public String getName(){
  return this.name;
 }
 
 public int getWeight(){
  return this.weight;
 }
 
 public int getPrice(){
  return this.price;
 }
}