import java.util.ArrayList;

import java.util.List;

public class StringPermutations {

public static void main(String[] args) {

String test = "abcd";

stringPermutations(test);

}

private static List<char[]> stringPermutations(String inputStr){

char[] input = inputStr.toCharArray();

// System.out.println(input);

int[] visited = new int[input.length];

ArrayList<char[]> result = new ArrayList<char[]>();

for(int i = 0; i < visited.length; i++){

visited[i] = 0;

}

char[] word = new char[input.length];

doPermutations(input, visited, word, 0, input.length);

return result;

}

private static void doPermutations(char[] input, int[] visited, char[] word, int count, int length){

if(count == length){

System.out.println(word);

return;

}

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

if(visited[i] == 1){

continue;

}

else{

word[count] = input[i];

visited[i] = 1;

doPermutations(input, visited, word, count + 1, length);

visited[i] = 0;

}

}

}

}