solves check if all chars have same frequency

Author: anishLearnsToCode

README.md

@@ -466,7 +466,7 @@
 | 1929 | [Concatenation of Array](https://leetcode.com/problems/concatenation-of-array)                                                                            |                                                              [![Java](assets/java.png)](src/ConcatenationOfArray.java)                                                               |                                                                                                                                   |
 | 1933 | 🔒 [Check If String Is Decomposable Into Value EqualSubstrings](https://leetcode.com/problems/check-if-string-is-decomposable-into-value-equal-substring) |                                                                                                                                                                                      |                                                                                                                                   |
 | 1935 | [Maximum Number of Words You Can Type](https://leetcode.com/problems/maximum-number-of-words-you-can-type)                                                |                                                         [![Java](assets/java.png)](src/MaximumNumberOfWordsYouCanType.java)                                                          |                                                                                                                                   |
-| 1941 | [Check if All Characters Have Equal Number of Occurrences](https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences)        |                                                                                                                                                                                      |                                                                                                                                   |
+| 1941 | [Check if All Characters Have Equal Number of Occurrences](https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences)        |                                                [![Java](assets/java.png)](src/CheckIfAllCharactersHaveEqualNumberOfOccurrences.java)                                                 |                                                                                                                                   |
 | 1945 | [Sum of Digits of String After Convert](https://leetcode.com/problems/sum-of-digits-of-string-after-convert)                                              |                                                                                                                                                                                      |                                                                                                                                   |
 | 1952 | [Three Divisors](https://leetcode.com/problems/three-divisors)                                                                                            |                                                                                                                                                                                      |                                                                                                                                   |
 | 1957 | [Delete Characters to Make Fancy String](https://leetcode.com/problems/delete-characters-to-make-fancy-string)                                            |                                                                                                                                                                                      |                                                                                                                                   |

src/CheckIfAllCharactersHaveEqualNumberOfOccurrences.java

@@ -0,0 +1,25 @@
+// https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences
+// T: O(|s|)
+// S: O(1)
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class CheckIfAllCharactersHaveEqualNumberOfOccurrences {
+    public boolean areOccurrencesEqual(String s) {
+        final Map<Character, Integer> charFrequencies = getCharacterFrequencies(s);
+        int commonFrequency = charFrequencies.get(s.charAt(0));
+        for (int frequency : charFrequencies.values()) {
+            if (frequency != commonFrequency) return false;
+        }
+        return true;
+    }
+
+    private Map<Character, Integer> getCharacterFrequencies(String s) {
+        final Map<Character, Integer> characterFrequencies = new HashMap<>();
+        for (int i = 0 ; i < s.length() ; i++) {
+            characterFrequencies.put(s.charAt(i), characterFrequencies.getOrDefault(s.charAt(i), 0) + 1);
+        }
+        return characterFrequencies;
+    }
+}