Discussion About Ultra Fast Mathematicians

#1

This is Discussion thread about Ultra Fast Mathematicians

#2

import java.util.Scanner;
class Code {
public static void main(String a[]) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
for (int i = 0; i < n; i++) {
String first = sc.next();
String second = sc.next();
String ans="";
for(int j=0 ; j<first.length();j++){
ans = ans + (first.charAt(j) ^ second.charAt(j));
}
System.out.print(ans);
}
}
}

what’s the error in this one test case got failed

#3

import java.util.Scanner;
public class Main {

int arr1[]=new int[100];
int arr2[]=new int[100];
int arr3[]=new int[100];
String s1;
String s2;

void input()
{
	Scanner sc=new Scanner(System.in);
	System.out.print("");
	s1=sc.next();
	System.out.print("");
	s2=sc.next();

}

void convert()
{
	char ch;
	int x=0;
	for(int i=0;i<s1.length();i++)
	{
		ch=s1.charAt(i);
		x=(int)ch;
		arr1[i]=x;
	}

	for(int i=0;i<s2.length();i++)
	{
		ch=s2.charAt(i);
		x=(int)ch;
		arr2[i]=x;
	}
}

void compute()
{
	for(int i=0;i<s1.length();i++)
	{
		if(arr1[i]!=arr2[i])
		{
			arr3[i]=1;
		}
		else
		{
			arr3[i]=0;
		}
	}
}

void display()
{
	for(int i=0;i<s1.length();i++)
	{
		System.out.print(arr3[i]);
	}
}

public static void main(String[]args)
{
	Main obj=new Main();

	Scanner s=new Scanner(System.in);
	System.out.println();
	int t=s.nextInt();
	while(t>0)
	{
		obj.input();
		obj.convert();
		obj.compute();
		obj.display();
		t--;
	}
}

}

What’s the error in this?
I’m getting wrong answer