ReplaceNum.java

/* Substract any number between 0 to 1000000 each digit by 9
 * Input : 25843
 * Output : 74156
 * 
 * Input : 58462314
 * Output : Given integer is out of range
 */

import java.util.*;
public class ReplaceNum {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int rem, val=0;
        if(n>=0 && n<=1000000)
        {
            int m=0;
            while(n>0)
            {
                rem = n%10;
                val = (int)((9-rem)*Math.pow(10,m)+val);
                n = n/10;
                m++;
            }
            
            System.out.println(val);
        }
        else
        {
            System.out.println("Given integer is out of range");
        }
    }
}

/* ANOTHER SOLUTION
 * ---------------------------
import java.util.*;
public class test {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String num = sc.nextLine();
        int val = 0;
        if(Integer.parseInt(num)>=0 && Integer.parseInt(num)<=1000000)
        {
            for (int i = 0; i < num.length(); i++) 
            {
                int k = 9-Integer.parseInt(String.valueOf(num.charAt(i)));
                val = val*10 + k;
            }
            System.out.println(val);
        }
        else
        {
            
        }
    }
}

 */