Fractional Knapsack

//Fractional Knapsack
import java.util.*;

class Item {
    int profit;
    int weight;
    float ratio;

    Item(int profit, int weight) {
        this.profit = profit;
        this.weight = weight;
        ratio = (float) (profit / weight);
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int capacity = sc.nextInt();
        
        Item[] items = new Item[N];
        
        for (int i = 0; i < N; i++) {
            int profit = sc.nextInt();
            int weight = sc.nextInt();
            items[i] = new Item(profit, weight);
        }
        
        float profit = fractionalKnapsack(items, N, capacity);
        System.out.println("Total profit: " + profit);
    }
    
    public static float fractionalKnapsack(Item[] items, int N, int capacity) {
        Arrays.sort(items, Comparator.comparingDouble((Item item) -> item.ratio).reversed());
        
        float totalProfit = 0;
        int currentWeight = 0;
        
        for (Item item : items) {
            if (currentWeight + item.weight <= capacity) {
                currentWeight += item.weight;
                totalProfit += item.profit;
            } else {
                int remaining = capacity - currentWeight;
                totalProfit += item.profit * ((float) remaining / item.weight);
                break;
            }
        }
        return totalProfit;
    }
}

/*
Sample Test Case:

Input:
4
50
60 10
100 20
120 30
80 40

Output:
Total profit: 240.0
*/