用户输入价格的冒泡排序？

Question

我正在尝试对每个 taco (1-10) 的价格进行冒泡排序，同时让 taco 名称遵循其原始价格（不需要对 taco 名称进行排序）。但是，我在排序的 if 语句中收到错误消息。

Exception in thread "main" java.lang.Error:
Unresolved compilation problems: The type of the expression must be an array type but it resolved to int
Type mismatch: cannot convert from double to int
Type mismatch: cannot convert from double to int
Type mismatch: cannot convert from double to int
Type mismatch: cannot convert from double to int
Type mismatch: cannot convert from double to int
    at TacoSort.main(TacoSort.java:36)

我可能是冒泡排序不准确，还是我没有适当地合并字符串？

import java.util.Scanner;

class TacoSort 
{
    //Create a constant amount of temperatures
    public static int NUMBER_OF_TACOS = 10;
    public static int NUMBER_OF_PRICES = 10;
    public static void main(String[] args) 
    {
        // TODO Auto-generated method stub

        Scanner keyboard = new Scanner(System.in);
        System.out.println("Welcome to the taco price sorter! Enter 10 taco names and prices and I'll sort it!");

        //Populates array of 10 tacos
        //Prompts user to enter name of each taco

        String[] tacos = new String[NUMBER_OF_TACOS];
        for (int i = 0; i < NUMBER_OF_TACOS; i++) 
        {
            System.out.print("Enter the name of taco " + (i+1) + "\n");
            tacos[i] = keyboard.next();

            //Populates array of 10 prices
            //Prompts user to enter price of each taco
            double[] prices = new double[NUMBER_OF_PRICES];
            //for (int j = 0; j < NUMBER_OF_PRICES; j++) //

            System.out.print("Enter taco's price " + (i+1) + "\n");
            prices[i] = keyboard.nextDouble();
        }

        for(double i = 0; i < NUMBER_OF_PRICES; i++)
        {
            for(double j = i + 1; j < tacos.length; j++)
            {
                if(NUMBER_OF_PRICES[i] > tacos[(int) j])
                {
                    String temp = tacos[i];
                    tacos[i] = tacos[j];
                    tacos[i] = temp;
                }
            }
        }
        for(int i = 0; i < tacos.length; i++)
        {
            System.out.print(tacos[i] + " ");
        }
    }

}

Answer 1

请查看我的内联 cmets，我认为它们会对您有所帮助。 您的解决方案存在一些不同的问题，这些问题已在我的 cmets 中记录。最大的问题是您没有跟踪与 tacos 名称交换的价格，因为两者都有两个不同的数组。因此，如果您考虑一下，如果您交换 taco 名称，它将与不同的 tacos 价格相关联，这不是我们想要的。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class TacoSort {
    //Create a constant amount of temperatures
    public static int NUMBER_OF_TACOS = 5; //<-- you should consider only using one constant value since they will both always be the same
    public static int NUMBER_OF_PRICES = 5;

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

        BufferedReader keyboard = new BufferedReader(new InputStreamReader(System.in)); //<-- notice i changed replace the scanner with this line to allow spaces in between the name of the tacos
        System.out.println("Welcome to the taco price sorter! Enter 10 taco names and prices and I'll sort it!");

        //Populates array of 10 tacos
        //Prompts user to enter name of each taco

        String[] tacos = new String[NUMBER_OF_TACOS]; //<-- it would be a better practice to create a taco object which would have two values name and price.
        //Populates array of 10 prices
        //Prompts user to enter price of each taco
        double[] prices = new double[NUMBER_OF_PRICES]; //<-- error should initialize this array outside the loop or you will create a new one on every iteration
        for (int i = 0; i < NUMBER_OF_TACOS; i++) {
            System.out.print("Enter the name of taco " + (i + 1) + "\n");
            tacos[i] = keyboard.readLine(); //<-- you want to read in next line so you can have spaces in your taco names

            System.out.print("Enter taco's price " + (i + 1) + "\n");
            prices[i] = Double.parseDouble(keyboard.readLine());
        }

        for (int i = 0; i < NUMBER_OF_PRICES; i++) {
            for (int j = 1; j < NUMBER_OF_PRICES; j++) {
                if (prices[j] < prices[j - 1]) //<-- error here you need to compare prices not what you were doing before by comparing the max size of your array
                {
                    String temp = tacos[j];
                    tacos[j] = tacos[j - 1];
                    tacos[j - 1] = temp; //<-- error here should be swapping element j here

                    /* NOTE YOU NEED TO KEEP TRACK OF THE PRICES SWAP AS WELL */
                    double tempDouble = prices[j];
                    prices[j] = prices[j - 1];
                    prices[j - 1] = tempDouble;
                }
            }
        }
        System.out.println("Sorted Tacos are");
        for (int i = 0; i < tacos.length; i++) {
        System.out.println("Taco Prices " + tacos[i] + " " + prices[i] + " ");
    }
    }

}