exercise5_16.java

Introduction to java programming 一书中所有编程练习部分的源码

// Exercise5_16.java: 
import javax.swing.JOptionPane;

public class Exercise5_16 {
  public static void main(String[] args) {
    // Prompt the user to enter the number of students
    String numberString = 
      JOptionPane.showInputDialog("Enter the number of students");
    int numberOfStudents = Integer.parseInt(numberString);
    
    String[] names = new String[numberOfStudents];
    double[] scores = new double[numberOfStudents];

    // Enter student name and score
    for (int i = 0; i < scores.length; i++) {
      names[i] = JOptionPane.showInputDialog("Enter a student name");
      scores[i] = Double.parseDouble(
        JOptionPane.showInputDialog("Enter a student score"));
    }
    
    // Sort
    for (int i = scores.length - 1; i >= 1; i--) {
      // Find the maximum in the scores[0..i]
      double currentMax = scores[0];
      int currentMaxIndex = 0;

      for (int j = 1; j <= i; j++) {
        if (currentMax < scores[j]) {
          currentMax = scores[j];
          currentMaxIndex = j;
        }
      }

      // Swap scores[i] with scores[currentMaxIndex] if necessary;
      // Swap names[i] with names[currentMaxIndex] if necessary;
      if (currentMaxIndex != i) {
        scores[currentMaxIndex] = scores[i];
        scores[i] = currentMax;
        String temp = names[currentMaxIndex];
        names[currentMaxIndex] = names[i];
        names[i] = temp;        
      }
    }

    // Print names and scores
    for (int i = scores.length - 1; i >= 0; i--) {
      System.out.println(names[i] + "\t" + scores[i]);
    }
  }
}