數據結構-00 數組(無序數組)

1、用long[ ] 模擬

package org.gzw.arr;

public class MyArray {
	private long[] arr; 
	/* 有效數據的長度 */
	private int elements;

	public MyArray() {
		arr = new long[50];
	}

	public MyArray(int maxSize) {
		arr = new long[maxSize];
	}
	
	/**
	 * 添加數據
	 */
	public void insert(long value){
		arr[elements] = value;
		elements++;
	}
	
	/**
	 * 顯示數據
	 */
	public String display(){
		StringBuffer strbuf = new StringBuffer();
		strbuf.append("[ ");
		/*for(long l : arr){
			strbuf.append(l + ", ");
		}*/
		for(int i =0; i<elements;i++){
			strbuf.append(arr[i] + ", ");
		}
		strbuf.delete(strbuf.length()-1, strbuf.length());
		strbuf.append("]");
		return strbuf.toString();
	}
	
	/**
	 * 查詢數據，並返回位置索引
	 */
	public int search(long value){
		int i;
		for(i=0;i<elements;i++){
			if(arr[i] == value) break;
		}
		
		if(i==elements){
			return -1;
		}else{
			return i;
		}
	}
	
	/**
	 * 查找數據，更具索引來查
	 */
	public long get(int index){
		if(0<=index && index<elements){
			return arr[index]; 
		}else{
			throw new ArrayIndexOutOfBoundsException();
		}
	}
	
	/**
	 * 刪除數據
	 */
	public void delete(int index){
		if(0<=index && index<elements){
			for(int i=index;i<elements;i++){
				if(i<elements-1){
					arr[i] = arr[i+1];
				}else break;
				
			}
			elements--;
		}else{
			throw new ArrayIndexOutOfBoundsException();
		}
	}
	
	/**
	 * 更新數據
	 */
	public void change(int index, long value){
		if(0<=index && index<elements){
			arr[index] = value;
		}else{
			throw new ArrayIndexOutOfBoundsException();
		}
	}
}

2、測試

package org.gzw.arr;

public class TestMyArray {
	
	public static void main(String[] args) {
		MyArray myArr = new MyArray(6);
		myArr.insert(1);
		myArr.insert(139);
		myArr.insert(229);
		myArr.insert(9);
		myArr.insert(19);
		myArr.insert(39);
		System.out.println(myArr.display());
		System.out.println(myArr.search(229));
		System.out.println(myArr.search(88));
		System.out.println(myArr.get(2));
		//System.out.println(myArr.get(-1));
		
		myArr.delete(2);
		System.out.println(myArr.display());
		
		myArr.change(1, 888);
		System.out.println(myArr.display());
	}
}