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