solves #2729: Check if The Number is Fascinating in java

Author: anishLearnsToCode

README.txt

@@ -830,7 +830,7 @@
 | 2716 | [Minimize String Length](https://leetcode.com/problems/minimize-string-length)                                                                                         |                                                                                   [![Java](assets/java.png)](src/MinimizeStringLength.java)                                                                                      |                                                                                                                                   |
 | 2717 | [Semi-Ordered Permutation](https://leetcode.com/problems/semi-ordered-permutation)                                                                                     |                                                                                   [![Java](assets/java.png)](src/SemiOrderedPermutation.java)                                                                                                                                               |                                                                                                                                   |
 | 2728 | [Count Houses in a Circular Street](https://leetcode.com/problems/count-houses-in-a-circular-street)                                                                   |                                                                                                                                                                                                                                  |                                                                                                                                   |
-| 2729 | [Check if The Number is Fascinating](https://leetcode.com/problems/check-if-the-number-is-fascinating)                                                                 |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2729 | [Check if The Number is Fascinating](https://leetcode.com/problems/check-if-the-number-is-fascinating)                                                                 |                                                                                   [![Java](assets/java.png)](src/CheckIfTheNumberIsFascinating.java)                                                                                                                                               |                                                                                                                                   |
 | 2733 | [Neither Minimum nor Maximum](https://leetcode.com/problems/neither-minimum-nor-maximum)                                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2739 | [Total Distance Traveled](https://leetcode.com/problems/total-distance-traveled)                                                                                       |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2744 | [Find Maximum Number of String Pairs](https://leetcode.com/problems/find-maximum-number-of-string-pairs)                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |

src/CheckIfTheNumberIsFascinating.java

@@ -0,0 +1,22 @@
+// https://leetcode.com/problems/check-if-the-number-is-fascinating
+// T: O(log(N))
+// S: O(1)
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class CheckIfTheNumberIsFascinating {
+    public boolean isFascinating(int number) {
+        final String modifiedNumber = "" + number + (2 * number) + (3 * number);
+        final Set<Character> digits = toSet(modifiedNumber);
+        return digits.size() == 9 && !digits.contains('0') && modifiedNumber.length() == 9;
+    }
+
+    private Set<Character> toSet(String str) {
+        final Set<Character> set = new HashSet<>();
+        for (int i = 0 ; i < str.length() ; i++) {
+            set.add(str.charAt(i));
+        }
+        return set;
+    }
+}