Java数据结构（数组篇）

小C最近开学数据结构，在此记录下学习历程。

首先：数组的增删改查

package ch01Array;

public class MyArray {

	//数组
	private long[] arr;
	
	//数组中有效数据的大小
	private int elems;
	
	//默认构造函数
	public MyArray(){
		arr = new long[50];
	}
	
	public MyArray(int max){
		arr = new long[max];
	}
	
	//插入数据
	public void insert(long value){
		arr[elems] = value;
		elems++;
	}	
	
	//显示数据
	public void display(){
		for (int i = 0; i < elems; i++) {
			System.out.print(arr[i] + " ");
		}
		System.out.println();
	}
	
	//查找数据
	public int find(long searchKey){
		int i;
		for(i = 0; i < elems; i++){
			if(arr[i] == searchKey)
				break;
		}
		if(i == elems)
			return -1;
		else
			return i;
	}
	
	//删除数据
	public void delete(long deleteKey){
		if(-1 != find(deleteKey)){
			for(int i = find(deleteKey); i < elems; i++){
				arr[i] = arr[i + 1];
			}
		}else
			System.out.println("查找不到指定数据，删除失败");
	}
	
	//修改数据
	public void change(long oldValue, long newValue){
		if(-1 != find(oldValue))
			arr[find(oldValue)] = newValue;
		else
			System.out.println("查找不到指定数据，修改失败");
	}
}

测试：

package ch01Array;

public class TestMyArray {

	public static void main(String[] args) {
		
		MyArray myArray = new MyArray();
		myArray.insert(4);
		myArray.insert(6);
		myArray.insert(35);
		myArray.insert(23);
		myArray.insert(89);
		myArray.display();
		
		System.out.println(myArray.find(23));
		
		myArray.delete(5);
		myArray.display();
		
		myArray.change(35, 45);
		myArray.display();
	}
}

有序插入和二分法查找：

package ch01Array;

public class MyOrderArray {

	//数组
	private long[] arr;
	
	//数组中有效数据的大小
	private int elems;
	
	//默认构造函数
	public MyOrderArray(){
		arr = new long[50];
	}
	
	public MyOrderArray(int max){
		arr = new long[max];
	}
	
	//有序插入数据
	public void insert(long value){
		int i;
		for(i = 0; i < elems; i++){
			if(arr[i] > value)
				break;
		}
		for(int j = elems; j > i; j--){
			arr[j] = arr[j - 1];
		}
		arr[i] = value;
		elems++;
	}
	
	//二分法查找
	public int binaryFind(long searchKey){
		int ins = 0;
		int low = 0;
		int pow = elems;
		
		while(true){
			ins = (low + pow) / 2;
			if(arr[ins] == searchKey)
				return ins;
			else if(low > pow)
				return -1;
			else
				if(arr[ins] > searchKey)
					pow = ins - 1;
				else
					low = ins + 1;
		}
	}
	
	//显示数据
	public void display(){
		for (int i = 0; i < elems; i++) {
			System.out.print(arr[i] + " ");
		}
		System.out.println();
	}
	

}

测试：

package ch01Array;

public class TestMyOrderArray {

	public static void main(String[] args) {
		
		MyOrderArray myArray = new MyOrderArray();
		myArray.insert(56);
		myArray.insert(6);
		myArray.insert(35);
		myArray.insert(23);
		myArray.insert(89);
		myArray.display();
		
		System.out.println(myArray.binaryFind(35));
	}
}

数组对象存储

对象类

package ch01Array;

public class Person {

	private String name;	//姓名
	private int age;		//年龄
	private String sex;		//性别
	
	public Person(String name, int age, String sex) {
		super();
		this.name = name;
		this.age = age;
		this.sex = sex;
	}
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	
	public void display(){
		System.out.print("姓名：" + this.name);
		System.out.print("，年龄：" + this.age);
		System.out.print("，性别：" + this.sex);
		System.out.println();
	}
	
}

对象数组

package ch01Array;

public class PersonArray {

	//数组
	private Person[] arr;
	
	//数组中有效数据的大小
	private int elems;
	
	//默认构造函数
	public PersonArray(){
		arr = new Person[50];
	}
	
	public PersonArray(int max){
		arr = new Person[max];
	}
	
	//插入数据
	public void insert(Person person){
		arr[elems] = person;
		elems++;
	}	
	
	//显示数据
	public void display(){
		for (int i = 0; i < elems; i++) {
			arr[i].display();
		}
		System.out.println();
	}
	
	//查找数据
	public int find(String name){
		int i;
		for(i = 0; i < elems; i++){
			if(arr[i].getName().equals(name))
				break;
		}
		if(i == elems)
			return -1;
		else
			return i;
	}
	
	//删除数据
	public void delete(String name){
		if(-1 != find(name)){
			for(int i = find(name); i < elems; i++){
				arr[i] = arr[i + 1];
			}
		}else
			System.out.println("查找不到指定数据，删除失败");
		elems--;
	}
	
	//删除数据
	public void delete(Person person){
		if(find(person.getName()) == -1)
			System.out.println("查找不到指定数据，删除失败");
		else
			for(int i = find(person.getName()); i < elems; i++){
				arr[i] = arr[i + 1];
			}
		elems--;
	}
	
	//修改数据
	public void change(Person oldPerson, Person newPerson){
		if(-1 != find(oldPerson.getName()))
			arr[find(oldPerson.getName())] = newPerson;
		else
			System.out.println("查找不到指定数据，修改失败");
	}
}

测试类：

package ch01Array;

public class TestPersonArray {

	public static void main(String[] args) {
		PersonArray pa = new PersonArray();
		
		//创建对象
		Person p1 = new Person("张三",20,"男");
		Person p2 = new Person("李四",21,"男");
		Person p3 = new Person("王五",22,"女");
		Person p4 = new Person("赵六",23,"男");
		Person p5 = new Person("李斯",24,"男");
		
		//插入操作
		pa.insert(p1);
		pa.insert(p2);
		pa.insert(p3);
		pa.insert(p4);
		pa.insert(p5);
		pa.display();

		//删除操作
		pa.delete("李斯");
		pa.display();
		
		//删除操作
		pa.delete(p2);
		pa.display();
	}
}