GFG.java

import java.util.Scanner;
import java.util.LinkedList;
class GFG {
    public static int counter;
    public static void BFS(int num, int x, int[] a){
        LinkedList<Integer> q = new LinkedList<>();
        q.add(num);
        
        while(q.size()!=0){
            int current = q.poll();
            if(current <= x){
                a[++counter] = current;

                int last_digit = current%10;
                
                if(last_digit == 0){
                    q.add((current*10) + (last_digit+1));
                } else if(last_digit == 9){
                    q.add((current*10) + (last_digit-1));
                } else{
                    q.add((current*10) + (last_digit-1));
                    q.add((current*10) + (last_digit+1));
                }
            }
        }
    }
    
    public static void printAllnumbers(int n, int a[]){
        a[0] = 0;
        for(int i=1;i<=9&&i<=n;i++){
            BFS(i, n, a);
        }
        for(int i=0;i<=counter;i++){
            System.out.print(a[i]+ " ");
        }
        System.out.println();
    }
	public static void main (String[] args) {
		Scanner in = new Scanner(System.in);
		int t = in.nextInt();
		while(t-->0){
		    counter = 0;
		    int n = in.nextInt();
		    int a[] = new int[n+1];
		    printAllnumbers(n, a);
		}
	}
}