solves count largest grop

Author: anishLearnsToCode

Diff for: README.md

@@ -355,7 +355,7 @@
 | 1385 | [Find The Distance Value Between 2 Arrays](https://leetcode.com/problems/find-the-distance-value-between-two-arrays)                                 |                                                      [![Java](assets/java.png)](src/FindTheDistanceValuesBetweenTwoArrays.java)                                                      |                                                                                                                                   |
 | 1389 | [Create Target Array in Given Order](https://leetcode.com/problems/create-target-array-in-the-given-order)                                           |                                                          [![Java](assets/java.png)](src/CreateTargetArrayInGivenOrder.java)                                                          |                                                                                                                                   |
 | 1394 | [Find Lucky Integer In An Array](https://leetcode.com/problems/find-lucky-integer-in-an-array)                                                       |                                                          [![Java](assets/java.png)](src/FindTheLuckyIntegerInAnArray.java)                                                           |                                                                                                                                   |
-| 1399 | [Count Largest Group](https://leetcode.com/problems/count-largest-group)                                                                             |                                                                                                                                                                                      |                                                                                                                                   |
+| 1399 | [Count Largest Group](https://leetcode.com/problems/count-largest-group)                                                                             |                                                                [![Java](assets/java.png)](src/CountLargestGroup.java)                                                                |                                                                                                                                   |
 | 1403 | [Minimum Subsequence in Non-Increasing Order](https://leetcode.com/problems/minimum-subsequence-in-non-increasing-order)                             |                                                                                                                                                                                      |                                                                                                                                   |
 | 1408 | [String Matching In An Array](https://leetcode.com/problems/string-matching-in-an-array)                                                             |                                                                                                                                                                                      |                                                                                                                                   |
 | 1413 | [Minimum Value To Get Positive Step By Step Sum](https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum)                       |                                                                                                                                                                                      |                                                                                                                                   |

Diff for: src/CountLargestGroup.java

@@ -0,0 +1,36 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class CountLargestGroup {
+    public int countLargestGroup(int n) {
+        Map<Integer, Integer> sumOfDigitsFrequencies = getFrequenciesOfSumOfDigits(n);
+        int largestGroupSize = 0, largestGroupFrequency = 0;
+        for (int groupSize : sumOfDigitsFrequencies.values()) {
+            if (groupSize > largestGroupSize) {
+                largestGroupSize = groupSize;
+                largestGroupFrequency = 1;
+            } else if (largestGroupSize == groupSize) {
+                largestGroupFrequency++;
+            }
+        }
+        return largestGroupFrequency;
+    }
+
+    private Map<Integer, Integer> getFrequenciesOfSumOfDigits(int N) {
+        Map<Integer, Integer> frequencies = new HashMap<>();
+        for (int number = 1 ; number <= N ; number++) {
+            int sumOfDigits = sumOfDigits(number);
+            frequencies.put(sumOfDigits, frequencies.getOrDefault(sumOfDigits, 0) + 1);
+        }
+        return frequencies;
+    }
+
+    private int sumOfDigits(int number) {
+        int sum = 0;
+        while (number > 0) {
+            sum += number % 10;
+            number /=  10;
+        }
+        return sum;
+    }
+}