Fractional Knapsack Problem

#include <iostream>
#include <string>
#include <sstream>
#include <iomanip>
#include <algorithm>
#include <cstdio>
#define SIZE 100
#define TAB 8
using namespace std;

struct item {
    int ID;
    int weight;
    int value;
    double wm;
    double taken;
};


bool comp(struct item X, struct item Y) {
    return X.wm > Y.wm;
}


double fillUpKnapsack(struct item A[], int numberOfItems, int W) {
    int remainingSpace = W;
    double cost = 0.0;

    for (int i = 0; i < numberOfItems && remainingSpace; i++) {
        if (A[i].weight <= remainingSpace) {
            cost += A[i].value;
            A[i].taken = 1.0;
            remainingSpace -= A[i].weight;
        }
        else {
            cost += 1.0 * A[i].value / A[i].weight * remainingSpace;
            A[i].taken = 1.0 * remainingSpace / A[i].weight;
            remainingSpace = 0;
        }
    }
    return cost;
}


void printItems(struct item A[], int numberOfItems) {
    cout << setw(TAB) << "ID";
    cout << setw(TAB) << "Value";
    cout << setw(TAB) << "Weight";
    cout << setw(TAB) << "V/W";
    cout << setw(TAB) << "Taken";
    cout << endl;
    for (int i = 0; i < numberOfItems; i++) {
        cout << setw(TAB) << A[i].ID;
        cout << setw(TAB) << A[i].value;
        cout << setw(TAB) << A[i].weight;
        cout << setw(TAB) << A[i].wm;
        cout << setw(TAB) << A[i].taken;
        cout << endl;
    }
    cout << endl;
}

int main() {
    freopen("input.txt", "r", stdin);

    string line;
    int W;

    cout << "Weight of Knapsack: ";
    getline(cin, line);
    stringstream(line) >> W;

    cout << "Items' Values and Weights: ";
    getline(cin, line);

    istringstream iss(line);

    struct item A[SIZE];

    int numberOfItems;
    for (numberOfItems = 0; iss >> line; numberOfItems++) {
        A[numberOfItems].ID = numberOfItems + 1;
        stringstream(line) >> A[numberOfItems].value;
        iss >> line;
        stringstream(line) >> A[numberOfItems].weight;
        A[numberOfItems].wm = 1.0 * A[numberOfItems].value / A[numberOfItems].weight;
        A[numberOfItems].taken = 0.0;
    }

    sort(A, A + numberOfItems, comp);

    double cost = fillUpKnapsack(A, numberOfItems, W);
    cout << "Maximum Cost: " << cost << endl;
    printItems(A, numberOfItems);

    return 0;
}


/*
SAMPLE INPUT:
5
10 4 15 5 6 1 14 2
*/