更新

exercise/src/Main.java

@@ -1,16 +1,48 @@
 import java.util.Scanner;
+import java.util.HashMap;
+import java.util.Map;
+import java.math.BigInteger;
 
 public class Main {
     public static void main(String[] args) {
         Scanner in = new Scanner(System.in);
-        String s = in.nextLine();
-        String[] words = s.split(" ");
-        StringBuilder sb = new StringBuilder(s.length());
-        for (int i = words.length - 1; i >= 0; i--) {
-            sb.append(words[i]);
-            if (i > 0) sb.append(' ');
+        if (!in.hasNext()) {
+            System.out.print("no");
+            in.close();
+            return;
         }
-        System.out.println(sb.toString());
+        int n = Integer.parseInt(in.next());
+        if (n <= 0) {
+            System.out.print("no");
+            in.close();
+            return;
+        }
+        
+        Map<String, Integer> cnt = new HashMap<>();
+        Map<String, Integer> first = new HashMap<>();
+        String best = null;
+        int bestCount = 0;
+        int bestIdx = Integer.MAX_VALUE;
+        int idx = 0;
+        while (idx < n && in.hasNext()) {
+            String raw = in.next();
+            String norm = new BigInteger(raw).toString();
+            int c = cnt.getOrDefault(norm, 0) + 1;
+            cnt.put(norm, c);
+            if (!first.containsKey(norm))
+                first.put(norm, idx);
+            int fi = first.get(norm);
+            if (best == null || c > bestCount || (c == bestCount && fi < bestIdx)) {
+                best = norm;
+                bestCount = c;
+                bestIdx = fi;
+            }
+            idx++;
+        }
+        if (best == null)
+            System.out.print("no");
+        else
+            System.out.print(best);
         in.close();
     }
 }