Example: Solve 0/1 Knapsack Problem in Java

// Solve 0/1 Knapsack Problem in Java
import java.util.Scanner;

public class Main {
    // It's the driver function
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        Main main = new Main();

        int[] val = {
            60,
            100,
            120
        };
        int[] wt = {
            10,
            20,
            30
        };
        int W = 50;
        int n = val.length;

        // This will print the solution of 0-1 Knapsack problem
        System.out.println("The solution of 0-1 Knapsack problem is: " + main.solveKnapSack(W, wt, val, n));
    }

    // This function will solve the 0 1 knapsack problem
    int solveKnapSack(int W, int wt[], int val[], int n) {
        if (n == 0 || W == 0)
            return 0; 

        // 1. If the weight of the nth item is more than 
        // 2. Knapsack capacity W, then this item cannot be included in the optimal solution
        if (wt[n - 1] > W)
            return this.solveKnapSack(W, wt, val, n - 1);

        // It returns the maximum of two cases:
        // 1. nth item included 
        // 2. not included 
        else
            return this.maxSize(val[n - 1] + this.solveKnapSack(W - wt[n - 1], wt, val, n - 1), this.solveKnapSack(W, wt, val, n - 1));
    }

    // This will return max size of the value
    int maxSize(int a, int b) {
        return (a > b) ? a : b;
    }
}