sequencelist.java

以数组为存储结构保存线性表

import java.awt.*;

public class SequenceList implements List
{
	private Object[] entry; //保存元素的数组 
	private int length;  //当前元素的个数
	private static final int MAX_SIZE = 50; //数组大小
	
	public void display()
	{
		for (int index = 0;index < length;index++)
			System.out.println(entry[index]);
		
	}
	
	public SequenceList()
	{
		length = 0;
		entry = new Object[MAX_SIZE];	
	}
	
	public SequenceList(int maxSize)
	{
  		length=0;
  		entry=new Object[maxSize];
 	}

    public SequenceList(Object[] str)
	{
		entry=new Object[MAX_SIZE];
		for(int i=0;i<str.length;i++)
		{
			entry[i]=str[i];
		}
		length=str.length;
	}
	
	
	public void clear()  //置空表 求表长
	{
		length =0;	
	}
	/*public void clear(SequenceList &T)

    {
    	T.a=new elemtype[maxsize]; //动态申请存储单元
		if(T.a==NULL) //申请不成功
		exit(1);
		T.len=0;
	}*/
	
	public int getLength()  //求表长
	{
		return length;	
	}
	
	public Object getEntry(int i)  //取出第i个元素
	{
		Object result = null;
		if ((i >=1)&&(i<=length))
			result = entry[i-1]; 	
		return result;
	}
	
	public boolean contains(Object anEntry)  //判断线性表是否包含元素anEntry
	{
		boolean found = false;
		for (int index = 0;!found && (index < length);index++)
		{
			if(anEntry.equals(entry[index])) 
				found = true;	
		}	
		return found;
	}
	
	public boolean isFull()
	{
		return length == entry.length;
	}
	
	public boolean add(int i,Object newEntry)  //将数据元素插入线性表中第i个元素之前

	{
		boolean isSuccessful = true;
		if(entry.length ==length)
			isSuccessful = false;
			
		if(i < 1 || i > length +1)
			isSuccessful = false;
				
		for (int index = length;index >= i;index--)
			entry[index] = entry[index -1];
		entry[i -1] = newEntry;
		++length;
		return isSuccessful;
	}
	
	public Object remove(int i)
	{
		Object result = null;
		if((i >=1) &&(i <= length))
		{
			result = entry[i-1];
			for(int index = i; index < length; index++)
				entry[index -1] = entry[index];
			length = length -1;	
		}
		return result;	
	}
	
	public boolean add(Object newEntry) 
	{
  		boolean isSuccessful = true;
  		if(!isFull()){
   			entry[length] = newEntry;
   			length++;
  		}
  		else
   			isSuccessful = false;
 		return isSuccessful;
 	}

	
	public boolean replace(int givenPosition, Object newEntry) 
	{
  		boolean isSuccessful = true;
  		if((givenPosition >= 1) && (givenPosition <= length))
   			entry[givenPosition-1] = newEntry;
  		else
   			isSuccessful = false;
  		return isSuccessful;
 	}

}