Question

You will be given a string, containing both uppercase and lowercase alphabets(numbers are not allowed).

Answer 1

Answer:

The Java code is given below with appropriate comments

Explanation:

import java.util.*;

class Main {

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

   static void printPerms(char ch[], int ind){

       //If end of string is reached, add it to set

       if(ind==ch.length){

           set.add(new String(ch));

           return;

       }

       for(int i=ind;i<ch.length;i++){

           //Only swap if lower case

           if((ch[i]>='a' && ch[i]<='z')&&((ch[ind]>='a' && ch[ind]<='z'))){

               char t  = ch[i];

               ch[i] = ch[ind];

               ch[ind] = t;

           }

           printPerms(ch,ind+1);

           if((ch[i]>='a' && ch[i]<='z')&&((ch[ind]>='a' && ch[ind]<='z'))){

               char t  = ch[i];

               ch[i] = ch[ind];

               ch[ind] = t;

           }

       }

   }

   public static void main(String[] args) {

       printPerms("aBbCc".toCharArray(),0);

       System.out.println(set);

   }

}