JavaProgramming/Recursion/PrintUniqueSubsequence.java at main · Varadraj75/JavaProgramming · GitHub

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// Print all unique subsequences of a string.

package Recursion;

import java.util.HashSet; // for the Hashset function

public class PrintUniqueSubsequence {

public static void subsequences(String str, int idx, String newStr, HashSet<String> set){

if(idx == str.length()){

if(set.contains(newStr)){

return;

}else{

System.out.println(newStr);

set.add(newStr);

return;

}

char currChar = str.charAt(idx);

// to be come the character in new string(newstr)

subsequences(str, idx+1, newStr+currChar, set);

// not to be come the character in the new string(newStr)

subsequences(str, idx+1, newStr, set);

}

public static void main(String[] args) {

String str = "bbb";

HashSet<String> set = new HashSet<>();

subsequences(str, 0, "", set);

}

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