数组的平均值并与名称相关联

Question

有人知道如何在这个简单的程序中显示参与者的平均比赛时间吗？ 将相关的跑步者姓名与时间一起显示也很棒。 我认为我有正确的数组结构并接受了用户输入。 感谢您提供的任何帮助。这是我的代码...

import java.util.Scanner;
 public class RunningProg
 {
    public static void main (String[] args)
    {
    int num;

    Scanner input= new Scanner (System.in);

    System.out.println("Welcome to Running Statistical Analysis Application");
    System.out.println("******************************************************************* \n");

    System.out.println("Please input number of participants (2 to 10)");

    num=input.nextInt();

    // If the user enters an invalid number... display error message... 
    while(num<2|| num >10)
    {
    System.out.println("Error invalid input! Try again! \nPlease input a valid number of participants (2-10)...");

        num=input.nextInt();
    }

    // declare arrays
    double resultArray [] = new double [num]; // create result array with new operator
    String nameArray [] = new String [num];// create name array with new operator
    // Using the num int will ensure that the array holds the number of elements inputed by user

      // loop to take in user input for both arrays (name and result)
    for (int i = 0 ; i < nameArray.length ; i++)
        {
            System.out.println ("Please enter a race participant Name for runner " + (i+1) );
            nameArray[i] = input.next();

            System.out.println ("Please enter a race result (time between 0.00 and 10.00) for runner " + (i+1) );
            resultArray[i] = input.nextDouble();
        }

Answer 1

这似乎是一个家庭作业问题，所以这里是你如何解决你的问题，伪代码：

参与者的总平均比赛时间是通过将所有结果相加并除以结果数量来计算的：

sum = 0
for i = 0 to results.length      // sum up all the results in a loop
    sum = sum + results[i]          
average = sum / results.length   // divide the sum by the amount of results to get the average

在读取用户输入并存储跑步者的姓名和结果时执行求和会更好。原因是它会更高效（不需要第二个循环来执行求和）并且代码会更简洁（它会更少）。

可以通过遍历保存名称和结果并在相应索引处打印值的两个数组来显示跑步者的时间：

for i = 0 to results.length
    print "Runner: " + names[i] + " Time: " + results[i]

之所以有效，是因为您拥有相同数量的结果和名称 (results.length == names.length)，否则您最终会遇到 ArrayIndexOutOfBounds 异常。

---

另一种方法是利用 Java 的面向对象特性并创建一个名为 Runner 的对象：

class Runner {
    String name;
    double result;
    Runner(String n, double r) {
        result = r;
        name = n;
    }
}

然后使用一个数组来存储这些跑步者：

Runner[] runners = new Runner[num];
for (int i = 0 ; i < num ; i++) {
    System.out.println ("Please enter a race participant Name for runner " + (i+1) );
    String name = input.next();
    System.out.println ("Please enter a race result (time between 0.00 and 10.00) for runner " + (i+1) );
    double result = input.nextDouble();
    runners[i] = new Runner(name, result);
}

然后您可以遍历跑步者数组并打印名称和结果...这是此的伪代码：

for i = 0 to runners.length
    print runners[i].name + " " + runners[i].result