Improved for loop in StringPermutation.java

README.md

@@ -17,6 +17,7 @@ Please contribute to this repository to help it make better. Any change like new
 * If you like eclipse instead of intellij install eclipse https://eclipse.org/downloads/
 
 <h3> Set up your desktop </h3>
+
 * Pull the git repository. Go to command line and type git clone https://github.com/mission-peace/interview.git
 * Go to root directory of checked out project.
 * Run ./gradlew idea to generate idea related classes

src/com/interview/recursion/StringPermutation.java

@@ -17,13 +17,7 @@ public class StringPermutation {
     public List<String> permute(char input[]) {
         Map<Character, Integer> countMap = new TreeMap<>();
         for (char ch : input) {
-            countMap.compute(ch, (key, val) -> {
-                if (val == null) {
-                    return 1;
-                } else {
-                    return val + 1;
-                }
-            });
+            countMap.put(ch, countMap.getOrDefault(ch, 0)+1);
         }
         char str[] = new char[countMap.size()];
         int count[] = new int[countMap.size()];