solves thousand seperator

Author: anishLearnsToCode

README.md

@@ -390,3 +390,4 @@
 | 1539 | [Kth Missing Positive Number](https://leetcode.com/problems/kth-missing-positive-number)                                                             |                                                            [![Java](assets/java.png)](src/KthMissingPositiveNumber.java)                                                             |                                                                                                                                   |
 | 1544 | [Make The String Great](https://leetcode.com/problems/make-the-string-great)                                                                         |                                                               [![Java](assets/java.png)](src/MakeTheStringGreat.java)                                                                |                                                                                                                                   |
 | 1550 | [Three Consecutive Odds](https://leetcode.com/problems/three-consecutive-odds)                                                                       |                                                              [![Java](assets/java.png)](src/ThreeConsecutiveOdds.java)                                                               |                                                                                                                                   |
+| 1556 | [Thousand Separator](https://leetcode.com/problems/thousand-separator)                                                                               |                                                                [![Java](assets/java.png)](src/ThousandSeparator.java)                                                                |                                                                                                                                   |

src/ThousandSeparator.java

@@ -0,0 +1,25 @@
+import java.util.LinkedList;
+
+public class ThousandSeparator {
+    public String thousandSeparator(int n) {
+        final LinkedList<Integer> list = getDigits(n);
+        final StringBuilder result = new StringBuilder();
+        for (int i = 3 ; !list.isEmpty() ; i = (i + 1) % 3) {
+            if (i == 0) result.append('.');
+            result.append(list.pop());
+        }
+        return result.reverse().toString();
+    }
+
+    private LinkedList<Integer> getDigits(int number) {
+        final LinkedList<Integer> result = new LinkedList<>();
+        if (number == 0) {
+            result.add(0);
+        }
+        while (number > 0) {
+            result.add(number % 10);
+            number /= 10;
+        }
+        return result;
+    }
+}