import java.util.ArrayList;import java.util.Scanner;import java.util.List;import java.util.concurrent.*; public class Main { private static volatile int index = 0; public static void main(String[] args) { Scanner sc = new Scanner(System.in); final List<String> list = new ArrayList<String>(); while (sc.hasNext()){ list.add(sc.nextLine()); } ExecutorService service = Executors.newFixedThreadPool(3); Future<Integer> result = service.submit(new Callable<Integer>() { @Override public Integer call() throws Exception { for (int j = 0; j < list.size(); j++) { for (int i = 0; i < list.get(j).length(); i++) { if (list.get(j).charAt(i) == 'u') { if (i + 1 < list.get(j).length() && list.get(j).charAt(i + 1) == '5') { if (i + 2 < list.get(j).length() && list.get(j).charAt(i + 2) == '1') { index++; } } } } } return index; } }); try { System.out.println(result.get()); } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } finally { service.shutdown(); } } }这样子AC了~