Merge 2 sorted array with o(1) space

Hi, I was doing this question, in the question it is mentioned that expected TC will be O((m+n)log(m+n))
ques link - https://practice.geeksforgeeks.org/problems/merge-two-sorted-arrays/0
my solution getting TLE. why?
Approach - taking 2 pointers one at the end of array1, and other at the starting of array2.
comparing both, if arr1>arr2, swap, and decrement pointer 1, and increment pointer 2, otherwise break.

import java.util.*;
import java.lang.*;
import java.io.*;
class GFG
 {
	public static void main (String[] args)
	 {
	    Scanner sc=new Scanner(System.in);
	    int t=sc.nextInt();
	    while(t-->0){
	        int size1=sc.nextInt();
	        int size2=sc.nextInt();
	        int[] arr1=new int[size1];
	        int[] arr2=new int[size2];
	        for(int i=0;i<size1;i++) arr1[i]=sc.nextInt();
	        for(int i=0;i<size2;i++)arr2[i]=sc.nextInt();
	        int i=size1-1;int j=0;
	        while(j<=size2-1&&i>=0){
	            if(arr2[j]<arr1[i]){
	                int temp=arr2[j];
	                arr2[j]=arr1[i];
	                arr1[i]=temp;
	                i--;j++;
	            }
	            else break;   
	        }
	        Arrays.sort(arr1);
	        Arrays.sort(arr2);
	        for(int k=0;k<arr1.length;k++)System.out.print(arr1[k]+" ");
	        for(int k=0;k<arr2.length;k++)System.out.print(arr2[k]+" ");
	        System.out.println();
	    }
	 }
}

please help me to get this resolve.

Thank you guys, it has solved by using bufferedReader

/* package codechef; // don't place package name! */
//@Author=Mr.Kashyap
import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
    
    public static void main(String[] args) throws IOException
    {
        Scan sc = new Scan();
        Print print=new Print();
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
        
	    int t=sc.scanInt();
	    while(t-->0){
	        int size1=sc.scanInt();
	        int size2=sc.scanInt();
	        int[] arr1=new int[size1];
	        int[] arr2=new int[size2];
	        for(int i=0;i<size1;i++) arr1[i]=sc.scanInt();
	        for(int i=0;i<size2;i++)arr2[i]=sc.scanInt();
	        int i=size1-1;int j=0;
	        while(j<=size2-1&&i>=0){
	            if(arr2[j]<arr1[i]){
	                int temp=arr2[j];
	                arr2[j]=arr1[i];
	                arr1[i]=temp;
	                i--;j++;
	            }
	            else break;   
	        }
	        Arrays.sort(arr1);
	        Arrays.sort(arr2);
	        for(int k=0;k<arr1.length;k++)bw.append(arr1[k]+" ");
	        for(int k=0;k<arr2.length;k++)bw.append(arr2[k]+" ");
	        bw.append("\n");
	    }
        
        bw.close();
    }
    
    /*BufferedWriter with scanInt, (long)scanDouble, scanString , bw.append(""+\n)*/
	
    static class Print
    {
        private final OutputStream out;
        /*public Print(OutputStream outputStream)
        {
            writer=new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }*/
        public Print()
        {
            this.out=System.out;
        }
        public void print(String str)throws IOException
        {
            //buf=str.getBytes();
            for (int i = 0; i < str.length(); i++)
            {
			/*if (i != 0)
			out.write(' ');*/
                out.write(str.charAt(i));
            }
        }
        public void printLine(String str)throws IOException
        {
            print(str);
            out.write('\n');
        }
        public void close()throws IOException
        {
            out.close();
        }
    }
    static class Scan
    {
        private byte[] buf=new byte[1024];
        private int index;
        private InputStream in;
        private int total;
        public Scan()
        {
            in=System.in;
        }
        public int scan()throws IOException
        {
            if(total<0)
                throw new InputMismatchException();
            if(index>=total)
            {
                index=0;
                total=in.read(buf);
                if(total<=0)
                    return -1;
            }
            return buf[index++];
        }
        public int scanInt()throws IOException
        {
            int integer=0;
            int n=scan();
            while(isWhiteSpace(n))
                n=scan();
            int neg=1;
            if(n=='-')
            {
                neg=-1;
                n=scan();
            }
            while(!isWhiteSpace(n))
            {
                if(n>='0'&&n<='9')
                {
                    integer*=10;
                    integer+=n-'0';
                    n=scan();
                }
                else throw new InputMismatchException();
            }
            return neg*integer;
        }
        public double scanDouble()throws IOException
        {
            double doub=0;
            int n=scan();
            while(isWhiteSpace(n))
                n=scan();
            int neg=1;
            if(n=='-')
            {
                neg=-1;
                n=scan();
            }
            while(!isWhiteSpace(n)&&n!='.')
            {
                if(n>='0'&&n<='9')
                {
                    doub*=10;
                    doub+=n-'0';
                    n=scan();
                }
                else throw new InputMismatchException();
            }
            if(n=='.')
            {
                n=scan();
                double temp=1;
                while(!isWhiteSpace(n))
                {
                    if(n>='0'&&n<='9')
                    {
                        temp/=10;
                        doub+=(n-'0')*temp;
                        n=scan();
                    }
                    else throw new InputMismatchException();
                }
            }
            return doub*neg;
        }
        public String scanString()throws IOException
        {
            StringBuilder sb=new StringBuilder();
            int n=scan();
            while(isWhiteSpace(n))
                n=scan();
            while(!isWhiteSpace(n))
            {
                sb.append((char)n);
                n=scan();
            }
            return sb.toString();
        }
        private boolean isWhiteSpace(int n)
        {
            if(n==' '||n=='\n'||n=='\r'||n=='\t'||n==-1)
                return true;
            return false;
        }
    }
    
}