1 import java.util.*; 2 import java.io.*; 3  4 public class Main { 5     public static void main(String[] args) throws IOException{ 6         // 计算程序运行时间  7         // Arrays 8         long st = System.currentTimeMillis(); 9         if ("abc" == "abc") System.out.println("Yes1");10         String str1 = new String("abc");11         String str2 = new String("abc");12         if (str1 == str2) System.out.println("Yes2");13         if (str1.equals(str2)) System.out.println("Yes3");14         15         //16         int[] t = {5, 1, 3, 2, 9};17         Arrays.sort(t);18         System.out.println(Arrays.toString(t));19         int[] s = new int[10];20         Arrays.fill(s, 33);21         System.out.println(Arrays.toString(s));22         // returns ((-insertion point) - 1) if key not exists.23         System.out.println(Arrays.binarySearch(t, 4));24         int cnt = 0;25         for (int i = 1; i < 100000000; i++) {cnt++;}26         long ed = System.currentTimeMillis();27         System.out.println("time: " + (ed - st));28         29         // 字符串hash30         String str = new String("hello world");31         System.out.println("hash Code: " + str.hashCode());32         33         // BufferReader缓冲与换行读取功能34         BufferedReader cin = new BufferedReader(new InputStreamReader(System.in));35         int sum = 0;36         String ss = null;37         while ((ss = cin.readLine()) != null) {38             sum += Integer.parseInt(ss);39         }40         System.out.println("the sum is: " + sum);41         42         //43         44     }45 }