Help me in solving DISTCODE problem

help
,
1

My issue

its jumping 2 whenever i recursive call it but i want it to jump only 1. and also when i run it its runs but when i submit it, it shows run time error

My code

/* package codechef; // don't place package name! */



import java.util.*;

import java.lang.*;

import java.io.*;



/* Name of the class has to be "Main" only if the class is public. */

class Codechef

{

    public static void recur(String s ,int idx , int count , HashSet<String> hash)

    {

        if(s.length()==1){

            System.out.println(count);

            return;

        }

        String temp = s.substring(idx , idx+2);

        if(!hash.contains(temp))

        {

            count++;

            hash.add(temp);

            //System.out.println(temp);

        }

        idx = idx + 1;

        recur(s.substring(idx) , idx , count , hash);

    }

	public static void main (String[] args) throws java.lang.Exception

	{

		Scanner sc = new Scanner(System.in);

		int t = sc.nextInt();

		while(t-->0)

		{

		    String s = sc.next();

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

		    recur(s ,0 , 0 , hash);

		    //System.out.println(ans);

		}

	}

}

Problem Link: Distinct Codes Practice Coding Problem - CodeChef

2

@co2annu
here plzz refer my c++ code for better understanding of the logic

#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
        int t;
        cin>>t;
        while(t--)
        {
            string s;
            cin>>s;
            set<string> st;
            for(int i=1;i<s.size();i++)
            {
                string ch;
                 ch+=s[i];
                ch+=s[i-1];
                st.insert(ch);
            }
            cout<<st.size()<<endl;
        }
}
3

thank you sir but i’m trying to do it with recursion .i’m having a problem which is
whenever i try to call recur function after 1st call it takes jump of 2 idx. for ex YBNA. so here the correct ans will be 3 as YB , BN , NA . but when i call it it jumps two idx . so my ans for YBNA is YB , NA so count is 2 . thats the problem im facing

4

@co2annu
just few little mistakes in your code .
I have corrected it in your code . Hope u will get it

/* package codechef; // don't place package name! */



import java.util.*;

import java.lang.*;

import java.io.*;



/* Name of the class has to be "Main" only if the class is public. */

class Codechef

{

    public static void recur(String s ,int idx , int count , HashSet<String> hash)

    {

        if(s.length()-1==idx){

            System.out.println(count);

            return;

        }

        String temp = s.substring(idx , idx+2);
        
        if(!hash.contains(temp))

        {

            count++;

            hash.add(temp);

            //System.out.println(temp);

        }

        recur(s, idx+1 , count , hash);

    }

	public static void main (String[] args) throws java.lang.Exception

	{

		Scanner sc = new Scanner(System.in);

		int t = sc.nextInt();

		while(t-->0)

		{

		    String s = sc.next();

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

		    recur(s ,0 , 0 , hash);

		    //System.out.println(ans);

		}

	}

}