Java solution || Using Hashset
\n# Approach\n1.Create a string(ans) which store the resultant string after concatenate.\n2.Create a Hashset which will store elements of string uniquely later.
\n# Approach\n1.Create a string(ans) which store the resultant string after concatenate.\n2.Create a Hashset which will store elements of string uniquely later.\n3.Now chech if ans contains "0" if yes return false. Also check if length of ans is greater than 9 if yes return false.\n4.Now iterate in ans and check if set already contains a element return false. Else add the element in the string.\n5.Now check if the size of hashset is 9 then return true. Else return false. \n\n# Code\n```\nimport java.util.*;\nclass Solution {\n    public boolean isFascinating(int n) {\n      String ans = String.valueOf(n) + String.valueOf(2*n) + String.valueOf(3*n);  \n        // int a = 2*n;\n        // int b = 3*n;\n        // String str = Integer.toString(n);\n        // String str1 = Integer.toString(a);\n        // String str2 = Integer.toString(b);\n        // String ans = str+str1+str2;\n\n        HashSet<Character> h = new HashSet<>();\n    \n       if(ans.contains("0")) return false;\n       if(ans.length()>9) return false;\n       for(int i=0; i<ans.length(); i++){\n           char ch = ans.charAt(i);\n           if(h.contains(ch)){\n               return false;\n           }else{\n               h.add(ch);\n           }\n       }\n       if(h.size()==9){\n       return true;\n       }\n        return false;\n    }\n}\n```
['Java']