Fractional Knapsack

Algorithm- Fractional Knapsack

import java.util.Scanner;

public class Knapsack01 {

     public static void main(String[] args) {

           Scanner scan = new Scanner(System.in);

           int n = scan.nextInt(); // 1

           int W = scan.nextInt(); // 1000

           float value[] = new float[n]; // 500

           float weight[] = new float[n]; // 30

           float ratio[] = new float[n];

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

                value[i] = scan.nextInt();

                weight[i] = scan.nextInt();

                ratio[i] = value[i] / weight[i];

           }

           float totalValue = knapSack01(W, value, weight, ratio, n);

           System.out.println(totalValue);

     }

     public static float knapSack01(float W, float[] value, float weight[], float ratio[],

                int n) {

           float V = 0;

           while (n>0 && W!=0) {

                int mI = maxIndex(n, ratio);

                float w=min(weight[mI],W);

                // W=40,weight[2]=30 // W=10,weight[0]=20;

                W = W - w;

                V = V + w*ratio[mI];

                weight[mI]=weight[mI]-w;

                ratio[mI] = 0;

                n--;

           }

           return V;

     }

     public static float min(float a,float b){

           return a>b?b:a;

     }

     public static int maxIndex(int n, float ratio[]) {

           float largest = Integer.MIN_VALUE;

           int lastIndex = 0;

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

                if (ratio[i] > largest) {

                     largest = ratio[i];

                     lastIndex = i;

                }

           }

           return lastIndex;

     }

}

Output:

Input: 3 50

60 20 100

50 120 30

Output: 180.0000