PHP-Fusion Powered Website - Articles: C++ Program to Solve the Fractional Knapsack Problem

Users Online

· Guests Online: 97

· Members Online: 0

· Total Members: 188
· Newest Member: meenachowdary055

Forum Threads

Newest Threads

No Threads created

Hottest Threads

No Threads created

Latest Articles

· Do while loop
· The for loop in C
· C while loop
· Pointers in C
· Functions in C

Oh no! Where's the JavaScript?
Your Web browser does not have JavaScript enabled or does not support JavaScript. Please enable JavaScript on your Web browser to properly view this Web site,
or upgrade to a Web browser that does support JavaScript; Firefox, Safari, Opera, Chrome or a version of Internet Explorer newer then version 6.

Articles Hierarchy

Articles Home » C++ » C++ Program to Solve the Fractional Knapsack Problem

C++ Program to Solve the Fractional Knapsack Problem

This is a C++ Program to solve fractional knapsack. The knapsack problem or rucksack problem is a problem in combinatorial optimization: Given a set of items, each with a mass and a value, determine the number of each item to include in a collection so that the total weight is less than or equal to a given limit and the total value is as large as possible. It derives its name from the problem faced by someone who is constrained by a fixed-size knapsack and must fill it with the most valuable items.

Here is source code of the C++ Program to Solve the Fractional Knapsack Problem. The C++ program is successfully compiled and run on a Linux system. The program output is also shown below.

/* program to implement fractional knapsack problem using greedy programming */

```
#include<iostream>
```
```
using namespace std;
```
```
int main()
```
```
{
```

    int array[2][100], n, w, i, curw, used[100], maxi = -1, totalprofit = 0;

```
    //input number of objects
```

    cout << "Enter number of objects: ";

```
    cin >> n;
```
```
    //input max weight of knapsack
```

    cout << "Enter the weight of the knapsack: ";

```
    cin >> w;
```

    /* Array's first row is to store weights

```
     second row is to store profits */
```
```
    for (i = 0; i < n; i++)
```
```
    {
```

        cin >> array[0][i] >> array[1][i];

```
    }
```
```
    for (i = 0; i < n; i++)
```
```
    {
```
```
        used[i] = 0;
```
```
    }
```
```
    curw = w;
```
```
    //loop until knapsack is full
```
```
    while (curw >= 0)
```
```
    {
```
```
        maxi = -1;
```

        //loop to find max profit object

```
        for (i = 0; i < n; i++)
```
```
        {
```

            if ((used[i] == 0) && ((maxi == -1) || (((float) array[1][i]

                    / (float) array[0][i]) > ((float) array[1][maxi]

                    / (float) array[0][maxi]))))

```
            {
```
```
                maxi = i;
```
```
            }
```
```
        }
```
```
        used[maxi] = 1;
```
```
        //decrease current wight
```
```
        curw -= array[0][maxi];
```
```
        //increase total profit
```
```
        totalprofit += array[1][maxi];
```
```
        if (curw >= 0)
```
```
        {
```

            cout << "\nAdded object " << maxi + 1 << " Weight: "

                    << array[0][maxi] << " Profit: " << array[1][maxi]

                    << " completely in the bag, Space left: " << curw;

```
        }
```
```
        else
```
```
        {
```

            cout << "\nAdded object " << maxi + 1 << " Weight: "

                    << (array[0][maxi] + curw) << " Profit: "

                    << (array[1][maxi] / array[0][maxi]) * (array[0][maxi]

                            + curw) << " partially in the bag, Space left: 0"

                    << " Weight added is: " << curw + array[0][maxi];

            totalprofit -= array[1][maxi];

            totalprofit += ((array[1][maxi] / array[0][maxi]) * (array[0][maxi]

```
                    + curw));
```
```
        }
```
```
    }
```

    //print total worth of objects filled in knapsack

    cout << "\nBags filled with objects worth: " << totalprofit;

```
    return 0;
```
```
}
```

Output:

$ g++ FractionalKnapsack.cpp
$ a.out
 
Enter number of objects: 3
Enter the weight of the knapsack: 50
10 60
20 100
30 120
 
Added object 1 Weight: 10 Profit: 60 completely in the bag, Space left: 40
Added object 2 Weight: 20 Profit: 100 completely in the bag, Space left: 20
Added object 3 Weight: 20 Profit: 80 partially in the bag, Space left: 0 Weight added is: 20
Bags filled with objects worth: 240

Users Online

Forum Threads

Latest Articles

Articles Hierarchy

C++ Program to Solve the Fractional Knapsack Problem

C++ Program to Solve the Fractional Knapsack Problem

Comments

Post Comment

Ratings