class Solution {    public List
     
       fullJustify(String[] words, int maxWidth) {        List
      
        res=new ArrayList
       
        ();        int idx=0;        while(idx
        
         0)                    {                        sb.append(" ");                        extra--;                    }                }                sb.append(words[i-1]);                res.add(sb.toString());            }            idx=i;        }        return res;    }}