frackanppsack.cpp

#include <iostream>
using namespace std;

class Item {
public:
    int weight, value;
    double ratio;
};

class FractionalKnapsack {
    Item *items;
    int n;

public:
    FractionalKnapsack(int size) {
        n = size;
        items = new Item[n];
    }

    void inputItems() {
        cout << "Enter weight and value for each item:\n";
        for (int i = 0; i < n; i++) {
            cin >> items[i].weight >> items[i].value;
            items[i].ratio = (double)items[i].value / items[i].weight;
        }
    }

    void sortItems() {
        for (int i = 0; i < n - 1; i++) {
            for (int j = 0; j < n - i - 1; j++) {
                if (items[j].ratio < items[j + 1].ratio) {
                    swap(items[j], items[j + 1]);
                }
            }
        }
    }

    double knapsack(int capacity) {
        sortItems();
        double maxValue = 0.0;
        for (int i = 0; i < n; i++) {
            if (capacity >= items[i].weight) {
                maxValue += items[i].value;
                capacity -= items[i].weight;
            } else {
                maxValue += items[i].ratio * capacity;
                break;
            }
        }
        return maxValue;
    }

    ~FractionalKnapsack() {
        delete[] items;
    }
};

int main() {
    int n, capacity;
    cout << "Enter number of items: ";
    cin >> n;
    FractionalKnapsack fk(n);
    fk.inputItems();
    cout << "Enter knapsack capacity: ";
    cin >> capacity;
    cout << "Maximum value in knapsack: " << fk.knapsack(capacity) << endl;
    return 0;
}


//This program sorts items by value-to-weight ratio and adds them fractionally to maximize the knapsack's value. Let me know if you need modifications!