查找10个主题的最大值

Question

我有一个程序可以通过文本文件进行排序，并使用10个线程提取最大值。然后，我怎样才能通过10个线程进行排序并找出这10个值的最高值？我的逻辑是将每个结果存储在一个数组中，并将结果与​​前一个结果进行比较，但我不确定如何通过线程正确地实现它。我添加了这个循环，但它是不正确的。任何帮助将不胜感激！

for (int x = 0; max <=max; x++) { 
       max = worker.getMax(); 
       System.out.println("Final Max " = max); 
      } 

这是包含上述代码的实际程序。没有这个，它运行良好。

import java.io.BufferedReader; 
import java.io.FileReader; 
import java.io.IOException; 

public class datafile{ 

    public static void main(String[] args) throws IOException { 
     int[] array = new int[100000]; 
     int count; 
     int index = 0; 
     String datafile = "dataset529.txt"; //string which contains datafile 
     String line; //current line of text file 

     try (BufferedReader br = new BufferedReader(new FileReader(datafile))) { //reads in the datafile 
      while ((line = br.readLine()) != null) { //reads through each line 
       array[index++] = Integer.parseInt(line); //pulls out the number of each line and puts it in numbers[] 
      } 
     } 



     Thread[] threads = new Thread[10]; 
     worker[] workers = new worker[10]; 


     int range = array.length/10; 
     for (count = 0; count < 10; count++) { 
      int startAt = count * range; 
      int endAt = startAt + range; 
      workers[count] = new worker(startAt, endAt, array); 

     } 

     for (count = 0; count < 10; count++) { 
      threads[count] = new Thread(workers[count]); 
      threads[count].start(); 
     } 

     boolean isProcessing = false; 
     do { 
      isProcessing = false; 
      for (Thread t : threads) { 
       if (t.isAlive()) { 
        isProcessing = true; 
        break; 
       } 
      } 
     } while (isProcessing); 

     for (worker worker : workers) { 
      System.out.println("Max = " + worker.getMax()); 
     } 

     for (int x = 0; max <=max; x++) { 
      max = worker.getMax(); 
      System.out.println("Final Max " = max); 
     } 

    } 


    public static class worker implements Runnable { 

     private int startAt; 
     private int endAt; 
     private int randomNumbers[]; 

     int max = Integer.MIN_VALUE; 

     public worker(int startAt, int endAt, int[] randomNumbers) { 
      this.startAt = startAt; 
      this.endAt = endAt; 
      this.randomNumbers = randomNumbers; 
     } 

     @Override 
     public void run() { 
      for (int index = startAt; index < endAt; index++) { 

       if (randomNumbers != null && randomNumbers[index] > max) 
        max = randomNumbers[index]; 
      } 
     } 

     public int getMax() { 
      return max; 
     } 

    } 
} 

Answer 1

基本上你的最大计算是错误的。这是更正的代码。

int finalMax = workers[0].getMax(); //Sets max as first worker's max 

for (int x = 1; x < workers.length; x++) { 
    if(finalMax < workers[x].getMax())//checks whether finalMax is less than worker's max at x'th position and if yes assigns it to finalMax   
     finalMax = workers[x].getMax();   
} 

System.out.println("Final Max " + finalMax);