update

1/A/Main.java

@@ -0,0 +1,52 @@
+import java.util.*;
+import java.io.*;
+
+public class Main {
+  public static void main(String[] args) throws IOException {
+    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    StringBuilder sb = new StringBuilder();
+
+    StringTokenizer st = new StringTokenizer(br.readLine());
+    int n = Integer.parseInt(st.nextToken());
+    int k = Integer.parseInt(st.nextToken());
+
+    Map<Character, TreeMap<Integer, TreeSet<String>>> index = new HashMap<>();
+    Map<String, Integer> counts = new HashMap<>();
+
+    for (int i = 0; i < n; i++) {
+      String word = br.readLine().trim();
+      char c = word.charAt(0);
+      counts.put(word, 0);
+      index
+          .computeIfAbsent(c, x -> new TreeMap<>())
+          .computeIfAbsent(0, x -> new TreeSet<>())
+          .add(word);
+    }
+
+    for (int i = 0; i < k; i++) {
+      String letter = br.readLine().trim();
+      char c = letter.charAt(0);
+
+      TreeMap<Integer, TreeSet<String>> byCount = index.get(c);
+
+      Map.Entry<Integer, TreeSet<String>> minEntry = byCount.firstEntry();
+      int minCount = minEntry.getKey();
+      TreeSet<String> minWords = minEntry.getValue();
+      String bestWord = minWords.first();
+
+      sb.append(bestWord).append('\n');
+
+      minWords.remove(bestWord);
+      if (minWords.isEmpty()) {
+        byCount.remove(minCount);
+      }
+      int newCount = minCount + 1;
+      byCount
+          .computeIfAbsent(newCount, x -> new TreeSet<>())
+          .add(bestWord);
+      counts.put(bestWord, newCount);
+    }
+
+    System.out.print(sb);
+  }
+}