Knapsack.java

import java.util.*;
public class FractionalKnapSnack {

    private static double calculateMaxP(Item[] ar,int w,Map<Integer,Double> hm) {
       
Arrays.sort(ar,( a,  b)->{
    double d1=(double)(a.profit/a.weight);
    double d2=(double)(b.profit/b.weight);

    if(d1<d2){
        return 1;
    }
    return -1;

});
double res=0;
for(int i=0;i<ar.length;i++){

        if(w-ar[i].weight>=0){
            w=w-ar[i].weight;
            res+=ar[i].profit;
            hm.put(ar[i].no,1D);
            
        }else{
res+=((w*1.0d)/ar[i].weight)*ar[i].profit;   
hm.put(ar[i].no,(w*1.0d)/ar[i].weight) ;
break;  
  }


}

 



        return res;
    }


    public static void main(String[] args) {
        Scanner  sc=new Scanner(System.in);
        System.out.println("enter no of objects");
        int n=sc.nextInt();
        System.out.println("enter the total weight of the knapsnack");
        int w=sc.nextInt();
        Item [] ar=new Item[n];
        for(int i=0;i<n;i++){
           System.out.println("enter profit for item :"+(i+1)); 
           int p=sc.nextInt();
           System.out.println("enter weight for item :"+(i+1)); 
           int wi=sc.nextInt(); 
            Item it=new Item(p, wi,i+1);
            ar[i]=it;

        }
        Map<Integer,Double> sol=new LinkedHashMap<>();
        double res=calculateMaxP(ar,w,sol);
        System.out.println(res);
        System.out.println(sol);
        
            }
        
           
}
public class Item{
    int profit;
    int weight;
    int no;
    Item(int p,int w,int no){
        profit=p;
        weight=w;
        this.no=no;
    }
}