更新

exercise/src/Main.java

@@ -1,48 +1,41 @@
 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);
-        if (!in.hasNext()) {
-            System.out.print("no");
-            in.close();
-            return;
-        }
-        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;
+        int n = in.nextInt();
+        int[] mention = new int[101];
+        boolean[][] by = new boolean[101][101];
+        for (int i = 0; i < n; i++) {
+            int sender = in.nextInt();
+            int k = in.nextInt();
+            for (int j = 0; j < k; j++) {
+                int id = in.nextInt();
+                if (id >= 0 && id <= 100) {
+                    mention[id]++;
+                    if (sender >= 0 && sender <= 100) by[id][sender] = true;
+                }
             }
-            idx++;
         }
-        if (best == null)
-            System.out.print("no");
-        else
-            System.out.print(best);
+        int bestId = 0;
+        int bestCount = -1;
+        for (int id = 0; id <= 100; id++) {
+            if (mention[id] > bestCount) {
+                bestCount = mention[id];
+                bestId = id;
+            }
+        }
+        System.out.println(bestId);
+        StringBuilder sb = new StringBuilder();
+        boolean first = true;
+        for (int s = 0; s <= 100; s++) {
+            if (by[bestId][s]) {
+                if (!first) sb.append(' ');
+                sb.append(s);
+                first = false;
+            }
+        }
+        System.out.println(sb.toString());
         in.close();
     }
 }