根據輸入查找兩個最高數字

Question

我負責完成用戶輸入學生姓名及其分數的程序。最後，該計劃應輸出分數最高的兩名學生，但我只能輸出分數最高的學生。

public class StudentScores 
{ 
public static void main(String[] args) 
{ 
    Scanner input = new Scanner(System.in); 
    System.out.print("Enter the number of students: "); 
    int numStudents = input.nextInt(); 
    System.out.print("Enter the student's name: "); 
    String Student1 = input.next(); 
    System.out.print("Enter the student's score: "); 
    int Score1 = input.nextInt(); 

    for (int i = 0; i < numStudents - 1; i++) 
    { 
     System.out.print("Enter the student's name: "); 
     String Student = input.next(); 
     System.out.print("Enter the student's score: "); 
     int Score = input.nextInt(); 

     if (Score > Score1) 
     { 
      Student1 = Student; 
      Score1 = Score; 
     } 
    } 
    System.out.println(Student1 + "'s score is " + Score1); 
}} 

我不確定的事情是如何弄清楚如何根據用戶輸入獲得Student2和Score2。我想使用數組，但我必須使用循環，所以這是我難倒的地方。

Answer 1

if (Score > Score1) 
{ 
    Student2 = Student1; 
    Score2 = Score1; 
    Student1 = Student; 
    Score1 = Score; 
} 
else if (Score > Score2) 
{ 
    Student2 = Student; 
    Score2 = Score; 
} 

Answer 2

您可以將學生存儲在數組中，然後對數組進行排序並返回前兩個。

或者如果你只想存儲最高的兩個分數，那麼你需要一些嵌套的比較器。

if (score > score2) { 
    if (score > score1) { 
     student2 = student1; 
     score2 = score1; 
     student1 = student; 
     score1 = score; 
    } else { 
     student2 = student; 
     score2 = score; 
    } 
} 

Answer 3

您將需要另一對變量Student2，Score2爲了跟蹤第二個學生。您可以將這兩個分數初始化爲一個低於最小值的值（例如，如果分數範圍爲0到10，則可以將它們初始化爲-1）;

String Student1 = "none", Student2 = "none"; 
int Score1 = -1, Score2 = -1; 


for (int i = 0; i < numStudents; i++) 
{ 
    System.out.print("Enter the student's name: "); 
    String Student = input.next(); 
    System.out.print("Enter the student's score: "); 
    int Score = input.nextInt(); 

if (Score > Score1) 
    { 
     Student2 = Student1; 
     Score2 = Score1; 
     Student1 = Student; 
     Score1 = Score; 
    } 
    else if (Score > Score2) {    
     Student2 = Student; 
     Score2 = Score; 
    } 
} 

Answer 4

您可以在Java中使用Arrays.sort() method。做到這一點的正確方法是創建一個名稱和分數的「學生」對象。這將是這個樣子：

public class Student implements Comparable { 
    private int score; 
    private String name; 

    public Student(String name, int score) 
    { // Constructor Code } 

使對象實現Comparable接口，這意味着寫compare method。在對學生數組進行排序後，打印數組中的前兩個名字。

Answer 5

爲了方便排序我建議類Student處理雙方比分並實現Comparable<Student>名稱（這會爲學生的任何作業量）。然後你必須編寫compareTo(Student student)方法，如果得分this大於student，則返回1，如果它們相等則返回0，否則返回-1。然後，您可以使用Collections.sort()（對於Collections，即ArrayList）和Arrays.sort()。

Answer 6

一個TreeMap<Integer, String>可以在這裏很有用，它是根據其鍵的自然順序進行排序：

TreeMap<Integer, String> map = new TreeMap<Integer, String>(); 

Scanner input = new Scanner(System.in); 
System.out.print("Enter the number of students: "); 
int numStudents = input.nextInt(); 

for (int i = 0; i < numStudents; i++) { 
    System.out.print("Enter the student's name: "); 
    String Student = input.next(); 
    System.out.print("Enter the student's score: "); 
    int Score = input.nextInt(); 
    map.put(Score, Student); 
} 

Map.Entry<Integer, String> entry1 = map.pollLastEntry(); 
Map.Entry<Integer, String> entry2 = map.pollLastEntry(); 
System.out.println("Highest score: " + entry1.getKey()); 
System.out.println("Highest scorer: " + entry1.getValue()); 
System.out.println("Second highest score: " + entry2.getKey()); 
System.out.println("Second highest scorer: " + entry2.getValue()); 

尋找第三，第四等最高分/得分將是這種方法容易得多。

Answer 7

package deneme; 

import java.util.Scanner; 

public class HighestTwoScore { 

    public static void main(String[] args) { 
     // TODO Auto-generated method stub 

     Scanner input = new Scanner(System.in); 

     System.out.print("Enter the number of student: "); 
     int numberOfStudents = input.nextInt(); 

     System.out.print("Enter the Students name and score: "); 
     String name1 = input.next(); 
     int score1 = input.nextInt(); 

     System.out.print("Enter the Students name and score: "); 
     String name2 = input.next(); 
     int score2 = input.nextInt(); 

     int controlScore = score1; 
     String controlName = name1; 
     if (score1 < score2) { 
      score1 = score2; 
      score2 = controlScore; 
      name1 = name2; 
      name2 = controlName; 
     } 

     int i = 0; 
     while (i < numberOfStudents - 2) { 
      System.out.print("Enter the Students name and score: "); 
      String name = input.next(); 
      int score = input.nextInt(); 

      if (score > score1) { 
       score2 = score1; 
       name2 = name1; 
       score1 = score; 
       name1 = name; 

      } else if (score > score2) { 
       score2 = score; 
       name2 = name; 
      } 

      i++; 
     } 
     System.out.println("Top student1 " + name1 + "'s score is " + score1); 
     System.out.println("Top student2 " + name2 + "'s score is " + score2); 
    } 

} 

Answer 8

import java.util.Scanner; 

public class TwoLargestNumbers{ 

    public static void main(String[] args) { 
     System.out.println("Enter number: "); 

     Scanner input = new Scanner(System.in); 

     int firstLarge = 0, secondLarge = 0; 

     for (int i = 1; i <= 10; i++) { 
      int num = input.nextInt(); 

      if (num >= firstLarge) { 
       secondLarge = firstLarge; 
       firstLarge = num; 
      } 

      if (num > secondLarge && num < firstLarge) 
       secondLarge = num; 

     } 

     System.out.println("First large number is: " + firstLarge); 
     System.out.print("Second large number is: " + secondLarge); 
    } 
}