2024-08-05

mjj111/빈도정렬.java

@@ -0,0 +1,53 @@
+import java.io.*;
+import java.util.*;
+
+public class 빈도정렬 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int N = Integer.parseInt(st.nextToken());
+        int COUNT = Integer.parseInt(st.nextToken());
+        Map<Integer, FreNumber> numbers = new HashMap<>();
+
+        st = new StringTokenizer(br.readLine());
+        for (int i = 0; i < N; i++) {
+            int now = Integer.parseInt(st.nextToken());
+            FreNumber nowFreNumber = numbers.getOrDefault(now, new FreNumber(i, now));
+            nowFreNumber.plusFre();
+            numbers.put(now, nowFreNumber);
+        }
+
+        List<FreNumber> answer = new ArrayList<>(numbers.values());
+        Collections.sort(answer);
+
+        for (FreNumber f : answer) {
+            for (int i = 0; i < f.fre; i++) {
+                System.out.print(f.number + " ");
+            }
+        }
+    }
+
+    static private class FreNumber implements Comparable<FreNumber> {
+        int number;
+        int index;
+        int fre = 0;
+
+        public FreNumber(int index, int number) {
+            this.index = index;
+            this.number = number;
+        }
+
+        public void plusFre() {
+            fre++;
+        }
+
+        @Override
+        public int compareTo(FreNumber op) {
+            if (this.fre == op.fre) {
+                return Integer.compare(this.index, op.index);
+            }
+            return Integer.compare(op.fre, this.fre);
+        }
+    }
+}