solves find the difference

Author: anishLearnsToCode

Diff for: src/FindTheDifference.java

@@ -0,0 +1,28 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class FindTheDifference {
+    public char findTheDifference(String s, String t) {
+        Map<Character, Integer> frequenciesOrigin = getFrequencies(s);
+        Map<Character, Integer> frequenciesNew = getFrequencies(t);
+        return difference(frequenciesOrigin, frequenciesNew);
+    }
+
+    private Map<Character, Integer> getFrequencies(String string) {
+        Map<Character, Integer> frequencies = new HashMap<>();
+        for (int index = 0 ; index < string.length() ; index++) {
+            char character = string.charAt(index);
+            frequencies.put(character, frequencies.getOrDefault(character, 0) + 1);
+        }
+        return frequencies;
+    }
+
+    private char difference(Map<Character, Integer> frequencies2, Map<Character, Integer> frequencies1) {
+        for (Character character : frequencies1.keySet()) {
+            if (frequencies1.get(character) != frequencies2.getOrDefault(character, 0)) {
+                return character;
+            }
+        }
+        return '\0';
+    }
+}