168 - 学生Map（hashmap）

[java]代码库

import java.util.*;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;

public class Main {
	public static void main(String[] args) throws ParseException
	{
		Scanner scan = new Scanner(System.in);

		int num = scan.nextInt();
		HashMap<Integer,Student> hmap = new HashMap<Integer,Student>();//hashmap自动按key值排序
		for(int i = 0; i < num; i++ )
		{
			int no = scan.nextInt();
			String name = scan.next();
			int score = scan.nextInt();
			Student s = new Student(no,name,score);
			hmap.put(no,s);
		}
		num = scan.nextInt();
		for(int i = 0; i < num; i++ )
		{
			String operate = scan.next();
			if(operate.equals("add"))//要用equals，不能用==
			{
				int no = scan.nextInt();
				String name = scan.next();
				int score = scan.nextInt();
				Student s = new Student(no,name,score);
				hmap.put(no,s);
			}
			else if(operate.equals("delete"))
			{
				int no = scan.nextInt();
				hmap.remove(no);
			}
			else if(operate.equals("set"))
			{
				int no = scan.nextInt();
				int score = scan.nextInt();
				hmap.get(no).setscore(score);
			}
		}
		Iterator iter = hmap.entrySet().iterator();
		while (iter.hasNext())
		{
			Map.Entry entry = (Map.Entry) iter.next();
			Object value = entry.getValue();
			System.out.println(value);
		}
	}
}
class Student
{
	private int no;
	private String name;
	private int score;
	public int getno()
	{
		return no;
	}
	public void setscore(int a)
	{
		score = a;
	}
	public Student(int a, String b, int c)
	{
		no = a;
		name = b;
		score = c;
	}
	public String toString()
	{
		return "no:"+no+" name:"+name+" score:"+score;
	}
}