Strings-difference in ascii codes

#1

https://online.codingblocks.com/player/25696/content/4778/4823

import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner scn = new Scanner(System.in);
String str = scn.nextLine();
StringBuilder sb = new StringBuilder(str);
int a=0;
int b =1;
int c = 1;
if(str.length()>=2 && str.length()<=1000){
for(int i =1;i<=str.length()-1;i++){
int as = ((int)(sb.charAt(b)))-((int)(sb.charAt(a)));
sb = sb.insert(c, as);
if(as>=0){
a = a+2;
b = b+2;
c = c+2;
}
else{
a =a+3;
b =b+3;
c = c+3;
}
}
System.out.println(sb);
}
}
}

one test case is failing
can nyone correct my code

#2

Hi @amanchaurasia1833,
In your code you have increase the value of a and b by 2 if ‘as’ is greater than zero and by 3 if ‘as’ is less than zero. this is done to go to the correct index for next iteration . But if the difference as is two digit number like 19 then increasing a and b by 2 will not work as then your a will point at 9 of number 19 instead of the character . Try taking ama as a testcase and dry run your algorithm on this … you will see the mistake.

#3

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