Duplicate Character Formatting

#1

import java.util.;
public class Main {
public static String DoubleCheck(String s, int n){
if (n==1 || n==0){
return s;
}
for(int i=0; i<n-1; i++){
if(s.charAt(i)==s.charAt(i+1)){
return s.substring(0,i+1) + "" + s.substring(i+1,n);
}
}
String ans = DoubleCheck(s, n-1);
return ans;
}
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
String s = sc.next();
int n = s.length();
String res = DoubleCheck(s,n);
System.out.println(res);
}
}

I wrote the above code. It is working for cases like “hello”, “john” etc. But it is not working for cases like “sssra”, “aaab” etc. What should I change in my code?

#2

So your code is working only when there is single occurrence of double character like in hello, because of your if code
if(s.charAt(i)==s.charAt(i+1)){
return s.substring(0,i+1) + “” + s.substring(i+1,n);
}
once if find a match like char(i) == char(i+1) , it just returns.

in this case , you don’t need both a loop and recursion. you need to think about it. why?
You can solve this either using loop or recursion, only one of this.
like

import java.util.;
public class Main {
public static String DoubleCheck(String s, int n){
if (n==1 || n==0){
return s;
}
for(int i=0; i<s.length()-1; i++){
if(s.charAt(i)==s.charAt(i+1)){
s = s.substring(0,i+1) + "" + s.substring(i+1,s.length());
}
}
return s;
}
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
String s = sc.next();
int n = s.length();
String res = DoubleCheck(s,n);
System.out.println(res);
}
}

this is a loop solution. just check if body carefully. try to write recursive version of it by yourself.

Thanks

#3

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