import java.util.Arrays;
import java.util.Scanner;

public class Permutations {

    private int count;
    
	private void swap(int i, int j, int [] p) {
		int tmp = p[i]; p[i] = p[j]; p[j] = tmp;
	}
		
	public void permute(int from, int [] permutation) {
		int i;
		if (from == permutation.length-1) {
			// suffix size is one, nothing to permute
			System.out.println(Arrays.toString(permutation));  
            count++;
		} else {
			// put every remaining item in first place
			// and recur
			for (i=from; i<permutation.length;i++) {
				// put i in first position of suffix
				swap(from,i, permutation); 
				// permute the rest
				permute(from+1, permutation);
				// put it back
				swap(from,i, permutation);				
			}
		}  
	}
	 
	public void generatePermutations(int n){
		 int [] permutation = new int[n];
		 //initialize P: [0, ...  ,(n-1)]
		 for (int i=0;i<n;i++) 
			 permutation[i]=i;
		 count = 0;
	     permute(0, permutation);
	     System.out.println("There are: " +count+ " permutations of length: " +n);
	}
	
	public static void main(String[] args) {
		// play with permutations
		Permutations ps = new Permutations();
		ps.generatePermutations(3);
	}

}