java-从链接列表中找到最大值

Question

Disclaimer: I am a very early student and am struggling to learn java. Please tell me if I'm leaving out any important information.

I am writing a program that prompts the user to do various operations to a linked list (add, remove, change value, etc.) but rather than storing a string or some primitive data type I am storing objects of type Student (which basically contains a string for the name of the student and an integer for their test score) and am stuck on how to find the maximum test score since I can't just find the highest Student.

Any help would be appreciated.

Answer 1

Well you can have two variables, one as the currentScore, and another as the newScore. And then traverse through each student object, get the test value, and then compare. If the new score is lower, then keep current. If new score is higher, replace current score with new score, and keep traversing. When you traverse the list, you have the highest score

Answer 2

You can iterate over the list as other answers described or you can use Collections.max method. To use this method your Student class should implement comperable interface.

public class Student implements Comparable<Student>

and you need to add compareTo method to the class:

@Override
public int compareTo(Student student)
{
    if (this.score > student.score)
    {
        return 1;
    }
    if (this.score < student.score)
    {
        return -1;
    }
    else
    {
        return 0;
    }
}

Now when you write Collections.max(list) you will get the Student with the highest score.

Answer 3

I wrote a simple program that matched your case.

Main Class:

import java.util.*;
import java.lang.Math; 

public class FindHighestScore
{
  public static void main(String[] args)
  {
    LinkedList<Student> studentLinkedlist = new LinkedList<Student>();

    studentLinkedlist.add(new Student("John",1)); // Adding 5 students for testing
    studentLinkedlist.add(new Student("Jason",5));
    studentLinkedlist.add(new Student("Myles",6));
    studentLinkedlist.add(new Student("Peter",10)); // Peter has the highest score
    studentLinkedlist.add(new Student("Kate",4));

    int temp = 0; // To store the store temporary for compare purpose
    int position = 0; // To store the position of the highest score student

    for(int i = 0; i < studentLinkedlist.size(); i ++){
      if(studentLinkedlist.get(i).getScore() > temp){ 
        temp = studentLinkedlist.get(i).getScore(); 
        position = i; 
      }
    }

  System.out.println("Highest score is: " + studentLinkedlist.get(position).getName()); 
  System.out.println("Score: " + studentLinkedlist.get(position).getScore());


  }
}

The student constructor class:

public class Student
{
  String name;
  int score;

  Student(){
  }

  Student(String name, int score){
    this.name = name;
    this.score = score;
  }

  String getName(){
    return this.name;
  }

  int getScore(){
    return this.score;
  }
}

The above program produce result as follows:

Highest score is: Peter
Score: 10