Recursion-and-Backtracking/UniqueSubsequence.java at main · Rohan-Beta/Recursion-and-Backtracking

31 lines (25 loc) · 781 Bytes

// Unique subsequence string

import java.util.*;

class Firstclass {

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

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

if(set.contains(newStr)) {

return;

}

else {

System.out.print(newStr + "\n");

set.add(newStr);

return;

}

char currChr = str.charAt(idx);

// to be

UniqueSubsequence(str, idx+1, newStr+currChr , set);

// not to be

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

}

public static void main(String args[]) {

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

UniqueSubsequence("aaa", 0, "", set);

}

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