ACM常用的Java代码

import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException{
        // 计算程序运行时间 
        // Arrays
        long st = System.currentTimeMillis();
        if ("abc" == "abc") System.out.println("Yes1");
        String str1 = new String("abc");
        String str2 = new String("abc");
        if (str1 == str2) System.out.println("Yes2");
        if (str1.equals(str2)) System.out.println("Yes3");
        
        //
        int[] t = {5, 1, 3, 2, 9};
        Arrays.sort(t);
        System.out.println(Arrays.toString(t));
        int[] s = new int[10];
        Arrays.fill(s, 33);
        System.out.println(Arrays.toString(s));
        // returns ((-insertion point) - 1) if key not exists.
        System.out.println(Arrays.binarySearch(t, 4));
        int cnt = 0;
        for (int i = 1; i < 100000000; i++) {cnt++;}
        long ed = System.currentTimeMillis();
        System.out.println("time: " + (ed - st));
        
        // 字符串hash
        String str = new String("hello world");
        System.out.println("hash Code: " + str.hashCode());
        
        // BufferReader缓冲与换行读取功能
        BufferedReader cin = new BufferedReader(new InputStreamReader(System.in));
        int sum = 0;
        String ss = null;
        while ((ss = cin.readLine()) != null) {
            sum += Integer.parseInt(ss);
        }
        System.out.println("the sum is: " + sum);
        
        //
        
    }
}