Refactor Day 6 2016 to use LongCountMap. Made code more concise using streams and project utilities.

Author: SimonBaars

src/main/java/com/sbaars/adventofcode/year16/days/Day6.java

@@ -1,8 +1,10 @@
 package com.sbaars.adventofcode.year16.days;
 
 import com.sbaars.adventofcode.year16.Day2016;
+import com.sbaars.adventofcode.common.map.LongCountMap;
 import java.util.*;
 import java.util.stream.Collectors;
+import java.util.stream.IntStream;
 
 public class Day6 extends Day2016 {
   public Day6() {
@@ -15,29 +17,19 @@ public static void main(String[] args) {
 
   private String decodeMessage(boolean mostCommon) {
     List<String> messages = dayStream().collect(Collectors.toList());
-    int messageLength = messages.get(0).length();
-    StringBuilder result = new StringBuilder();
-
-    for (int pos = 0; pos < messageLength; pos++) {
-      Map<Character, Integer> freq = new HashMap<>();
-      for (String message : messages) {
-        char c = message.charAt(pos);
-        freq.merge(c, 1, Integer::sum);
-      }
-
-      char selectedChar = freq.entrySet().stream()
-          .sorted((a, b) -> {
-            int comp = mostCommon ? b.getValue().compareTo(a.getValue()) : a.getValue().compareTo(b.getValue());
-            return comp != 0 ? comp : a.getKey().compareTo(b.getKey());
-          })
-          .map(Map.Entry::getKey)
-          .findFirst()
-          .orElseThrow();
-
-      result.append(selectedChar);
-    }
-
-    return result.toString();
+    return IntStream.range(0, messages.get(0).length())
+        .mapToObj(pos -> messages.stream()
+            .map(msg -> msg.charAt(pos))
+            .collect(LongCountMap.toCountMap()))
+        .map(freq -> freq.entrySet().stream()
+            .sorted((a, b) -> mostCommon ? 
+                b.getValue().compareTo(a.getValue()) : 
+                a.getValue().compareTo(b.getValue()))
+            .map(Map.Entry::getKey)
+            .findFirst()
+            .orElseThrow())
+        .map(String::valueOf)
+        .collect(Collectors.joining());
   }
 
   @Override