Question

我的数据结构课程项目需要帮助。我想读取存储在名为Employee.txt的文本文件中的10名员工数据并将其读入数组，然后将该数组传递到heapSort方法，并将已排序的员工打印到名为SortedEmployee.txt的输出文件中。由于某种原因，我的程序无法运行。有人可以帮忙吗？

班级员工

import java.util.ArrayList;
public class Employee
{
    public String empId , empName , empDept , empPos;
    public double empSalary;
    public int empServ;

Employee()
{
  empId = ("");
  empName = (""); 
  empDept = (""); 
  empPos = ("");
  empSalary = 0.0;
  empServ = 0;
}
Employee(String id ,String name, double salary, String dept , String pos, int serv)
{
  empId = id;
  empName = name;
  empDept = dept;
  empPos = pos;
  empSalary = salary;
  empServ = serv;
}
public void setId(String id)
{
  empId = id;
}           
public void setName(String name)
{
  empName = name;
}
public void setDept(String dept)
{
  empDept = dept;
} 
public void setPos(String pos)
{
  empPos = pos;
}
public void setSalary(double salary)
{
  empSalary = salary;
}
public void setServ(int serv)
{
  empServ = serv;
}       
public String getId()
{
  return empId;
}
public String getName()
{
  return empName;
}
public String getDept()
{
  return empDept;
}
public String getPos()
{
  return empPos;
}
public double getSalary()
{
  return empSalary;
}
public int getServ()
{
  return empServ;
}
public String toString()
{
  String str = "Employee Name : " + empName + "\nEmployee ID : " + empId +
                 "\nEmployee Deaprtment : " + empDept + "\nEmployee Position : " 
                 + empPos + "\nEmployee Salary : " + empSalary 
                 + "\nEmployee Years   Served : " + empServ;
  return str;
}
public int compareTo(Employee emp)
{
  int id = empId.compareToIgnoreCase(emp.empId);
  if (id != 0)
     return id;
  return 0;
}                  
}

Class HeapSort

import java.util.Scanner;
import java.util.ArrayList;
import java.io.*;

class zNode
{
   private int iData;             

public zNode(int key)           
{ 
  iData = key; 
}
public int getKey()
{ 
  return iData; 
}
public void setKey(int k)
{
  iData = k; 
}
} 


class HeapSort
{
   private int [] currArray;
   private int maxSize;          
   private int currentSize;
   private int currIndex;

HeapSort(int mx)            
{
  maxSize = mx;
  currentSize = 0;
  currArray = new int[maxSize];  
}

//buildheap
public boolean buildHeap(int [] currArray)
{
  int key = currIndex;
  if(currentSize==maxSize)
     return false;
  int newNode = key;
  currArray[currentSize] = newNode;
  siftUp(currArray , currentSize++);
  return true;
}

//siftup
public void siftUp(int [] currArray , int currIndex)
{
  int parent = (currIndex-1) / 2;
  int bottom = currArray[currIndex];

  while( currIndex > 0 && currArray[parent] < bottom )
  {
     currArray[currIndex] = currArray[parent];  
     currIndex = parent;
     parent = (parent-1) / 2;
  }  
  currArray[currIndex] = bottom;
 }

//siftdown
public void siftDown(int [] currArray , int currIndex)
{
  int largerChild;
  int top = currArray[currIndex];       
  while(currIndex < currentSize/2)       
  {                               
     int leftChild = 2*currIndex+1;
     int rightChild = leftChild+1;

     if(rightChild < currentSize && currArray[leftChild] < currArray[rightChild] )
        largerChild = rightChild;
     else
        largerChild = leftChild;

     if( top >= currArray[largerChild] )
        break;

     currArray[currIndex] = currArray[largerChild];
     currIndex = largerChild;            
   }  
   currArray[currIndex] = top;            
   }

//remove max element
public int removeMaxElement(int [] currArray)          
{                           
  int root = currArray[0];
  currArray[0] = currArray[--currentSize];
  siftDown(currArray , 0);
  return root;
}  

//heapsort
private void _sortHeapArray(int [] currArray)
{
  while(currentSize != 0)
  {
     removeMaxElement(currArray);
  }
}

public void sortHeapArray()
{
  _sortHeapArray(currArray);
} 

//hepify
private int[] heapify(int[] currArray) 
{
  int start = (currentSize) / 2;
  while (start >= 0) 
  {
     siftDown(currArray, start);
     start--;
  }
  return currArray;
}

//swap
private int[] swap(int[] currArray, int index1, int index2) 
{
  int swap = currArray[index1];
  currArray[index1] = currArray[index2];
  currArray[index2] = swap;
  return currArray;
}

//heapsort
public int[] _heapSort(int[] currArray) 
{
  heapify(currArray);
  int end = currentSize-1;
  while (end > 0) 
  {
     currArray = swap(currArray,0, end);
     end--;
     siftDown(currArray, end);
  }
  return currArray;
}
public void heapSort()
{  
  _heapSort(currArray);

}   

//main method
public static void main (String [] args) throws IOException
{
    HeapSort mySort = new HeapSort(10);
    Employee [] myArray = new Employee[10];

    String firstFile = ("Employee.txt");
    FileReader file = new FileReader(firstFile); 
    BufferedReader br = new BufferedReader(file);   

    String secondFile = ("SortedEmployee.txt");
    PrintWriter outputFile = new PrintWriter(secondFile);

    String[] currArray = new String[10];
String lineContent;
    while ((lineContent = br.readLine()) != null)
    {    
    for (int i = 0; i < currArray.length; i++)
    {
           lineContent = br.readLine();
           currArray[i] = String.valueOf(lineContent);
           mySort.heapSort(); 
           outputFile.println(mySort);
           }
         }         
    outputFile.close();
    System.out.print("Done");

     } 
    }

我知道问题出在while循环的main方法中，但我不知道如何解决它。

employee.txt中：

086244

Sally L. Smith

100000.00

Accounting

Manager

7

096586

Meredith T. Grey

150000.00

Physical Therapy

Doctor

9

875236

Christina R. Yang

190000.00

Cardiology

Resident

10

265893

George A. O'Malley

98000.00

Pediatrics

Attending

7
etc......

Answer 1

您尚未实施Comparable<Employee>。它应该是这样的。

public class Employee implements Comparable<Employee>{
    @Override
    public int compareTo(Employee emp){
       return this.empId.compareToIgnoreCase(emp.empId);
    }
}

只需使用Arrays.sort()方法对数组进行排序。

通过将txt文件和Pass数组引用变量传递给heapsort方法来创建数组

1 个答案: