Palindromic pattern

Here is the pattern:

        1
       212
      32123
     4321234
    543212345

Now let's code:

1. int n;

2. cin>>n;

3. for(int i=1;i<=n;i++){

4. int j;

5. for(j=1;j<=n-i;j++){

   cout<<" ";
   }

6. int k=i;

7. for(;j<=n;j++){

   cout<<k--<<" ";
   }

8. k=2;

9. for(;j<=i+n-1;j++){

   cout<<k++<<" ";
   }

10. cout<<endl;
    }