Java Permutations

import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;

public class permutations {
	public static void generatePermutations(int[] nums, int[] perm, boolean[] used, int n) {
		if (nums.length == n) {
			// perm now contains one permutation of nums.
			// Perform whatever operation you want. I printed here.
			//for (int k : perm)
			//	System.out.print(k + " ");
			//System.out.println();
		} else {
			// Try shoving every unused number into perm at index n
			for (int i = 0; i < nums.length; i++) {
				if (used[i])
					continue;
				perm[n] = nums[i];
				used[i] = true;
				generatePermutations(nums, perm, used, n + 1);
				used[i] = false;
			}
		}
	}
	public static void permute(int[] nums)
	{
		generatePermutations(nums, new int[nums.length], new boolean[nums.length], 0);
	}

	public void run() {
		int[] arr = new int[10];
		for( int i = 0; i < arr.length; i++ )
			arr[i] = i;
		permute(arr);
	}

	public void debug(Object n) {
		System.out.println(n);
	}

	static Scanner in = new Scanner(System.in);
	static PrintWriter out = new PrintWriter(System.out);

	public static void main(String[] args) throws FileNotFoundException {
//		in = new Scanner(new File("permutations.in"));
//		out = new PrintWriter(new File("permutations.out"));

		permutations permutations = new permutations();
		permutations.run();
	}
}