订单顺序翻转

Question

问题描述：-

我有两个文件。每个文件都有 order_number，这是一个随机的字母数字字符串，它们彼此唯一。 两个文件都包含相同数量的 order_number，如果一个 order_number 在一个文件中，则无论它在文件中的位置如何，它都必须存在于另一个文件中。

下面是苍蝇的例子：

• 文件1

  abc123
  def234
  skd109
  djkk09
  nknk323
  

• 文件2

  skd109
  def234
  abc123
  nknk323
  djkk09
  

现在我要编写一个以file1为参考的程序，看看哪些订单根据file2中的位置相对翻转。

例如考虑以上两个文件。 file1 中的 order_number abc123 位于位置 1，但在 file2 中位于位置 3，并且分别位于 file2 中的两个 order_number （ skd109 和 def234 ）之后。

Order_number def234 在 file2 中的 skd109 之后。

并且order_number djkk09 和nknk323 被翻转。

我的程序的输出应该是这样的：

    abc123 is flipped by 2 ( +ve sign because it came after )
    def234 is flipped by 0
    skd109 is flipped by -2 ( -ve sign because it came before )
    djkk09 is flipped by 1
    nknk323 is flipped by -1

注意：每个文件中都有超过百万条记录。所以解决方案应该是有效的。

下面是我的代码：-

import java.util.*;
import java.io.*;


public class Matching {
    public static void main( String args[]) throws IOException{

    /* Variable Declaration */  
    int ordersFlipped = 0;
    int ordersNotFlipped = 0;
    String lineFile1 = null;
    String lineFile2 = null;
    int indexFile2 = 0;
    int indexFile1 = 0;


    /*      Scanner     */  
    BufferedReader file2 = new BufferedReader(new FileReader("FlipAnalysis/file2"));
    BufferedReader file1 = new BufferedReader(new FileReader("file1"));

    /*      File Creation       */
    File file = new File("Result");

    /*      Objects to write into the files     */
    PrintWriter outputResult = new PrintWriter(file);

   /* Hash Map*/
    Map<String,Integer> map = new HashMap<String, Integer>();

    while ((lineFile2 = file2.readLine()) != null){
        indexFile2++;
        map.put(line,indexMe);
    }

    System.out.println("Map is ready. Now performing Matching.");

    while (( lineFile1 = inputFile1.readLine()) != null){
        indexFile1++;
        if(map.containsKey(lineFile1)){

            if(((indexFile - map.get(lineFile1))!= 0) 
                {
                    outputResult.println(lineFile1 + " Flipped by: " +(indexFile - map.get(lineFile1));
orderFlipped++;
}

                    else{
                        outputResult.println( lineFile1 + " Flipped by: 0" );
ordersNotFlipped++;

                    }
            }
        }





    outputResult.println("\n\n--------------------------------------------------------------\n"+ "Total Order Flipped: " +ordersFlipped);
    outputResult.println("\nOrder Not Flipped: " +ordersNotFlipped);
    outputResult.println("\nTotal Number of Orders: " + (ordersFlipped + ordersNotFlipped));
    System.out.println("Done!!");
    inputFile2.close();
    inputFile1.close();
    outputResult.close();
    }
}

Answer 1

假设您有 JDK 7 或更高版本。

public static void main(String args[]) throws Exception {
    System.out.println("Creating hashmap...");

    HashMap<String, Integer> newOrderNumberPositionMap = new HashMap<>();

    try (BufferedReader reader = new BufferedReader(new FileReader("d:\\test\\file2.txt"), 4096)) {
        String orderNumber;
        int lineNo = 1;
        while ((orderNumber = reader.readLine()) != null) {
            newOrderNumberPositionMap.put(orderNumber, lineNo);
            lineNo++;
        }
    }

    System.out.println("Map is ready. Now performing matching and writing result...");

    try (BufferedReader reader = new BufferedReader(new FileReader("d:\\test\\file1.txt"), 4096);
            BufferedWriter writer = new BufferedWriter(new FileWriter("d:\\test\\result.txt"), 4096)) {
        int ordersFlipped = 0;
        String orderNumber;
        int lineNo = 1;
        while ((orderNumber = reader.readLine()) != null) {
            int newLineNo = newOrderNumberPositionMap.get(orderNumber);

            writer.write(orderNumber);
            writer.write(" is flipped by ");
            writer.write(String.valueOf(newLineNo - lineNo));
            writer.newLine();

            if ((newLineNo - lineNo) != 0) {
                ordersFlipped++;
            }

            lineNo++;
        }

        writer.newLine();
        writer.write("--------------------------------------------------------------");
        writer.newLine();

        writer.write("Orders Flipped: ");
        writer.write(String.valueOf(ordersFlipped));
        writer.newLine();

        writer.write("Orders Not Flipped: ");
        writer.write(String.valueOf(newOrderNumberPositionMap.size() - ordersFlipped));
        writer.newLine();

        writer.write("Total Number of Orders: ");
        writer.write(String.valueOf(newOrderNumberPositionMap.size()));
        writer.newLine();

    }

    System.out.println("Done.");
}