数组的增删改查
public class MyArray {
private long[] arr;
//表示有效数据的长度
private int elements;
public MyArray(){
arr = new long[50];
}
public MyArray(int maxsize){
arr = new long[maxsize];
}
/**
* 添加数据
*/
public void insert(long value){
arr[elements] = value;
elements++;
}
/**
* 显示数据
*/
public void display(){
System.out.print("[");
for(int i=0;i<elements;i++){
System.out.print(" " +arr[i]+" ");
}
System.out.println("]");
}
/*
* 查找数据
*/
public int search(long value){
int i;
for(i=0;i<elements;i++){
if(value==arr[i]){
break;
}
}
if (i==elements){
return -1;
}else{
return i;
}
}
/*
* 查找数据,根据索引来查
*/
public long get(int index){
if(index>=elements || index<0){
throw new ArrayIndexOutOfBoundsException();
}else{
return arr[index];
}
}
/*
* 删除数据
*/
public void delete(int index){
if(index>=elements || index<0){
throw new ArrayIndexOutOfBoundsException();
}else{
for(int i=index;i<elements;i++){
arr[index] = arr[index+1];
}
elements--;
}
}
/*
* 更新数据
*/
public void change(int index,int newvalue){
if(index>=elements || index<0){
throw new ArrayIndexOutOfBoundsException();
}else{
arr[index] = newvalue;
}
}
public static void main(String[] args) {
MyArray arr = new MyArray();
arr.insert(3);
arr.insert(5);
arr.insert(6);
arr.insert(7);
arr.display();
// System.out.println(arr.search(6));
// System.out.println(arr.get(3));
arr.delete(0);
arr.display();
arr.change(0, 666);
arr.display();
}
}
有序数组
public class MyOrderArray {
private long[] arr;
//表示有效数据的长度
private int elements;
public MyOrderArray(){
arr = new long[50];
}
public MyOrderArray(int maxsize){
arr = new long[maxsize];
}
/**
* 添加数据
*/
public void insert(long value){
int i;
for(i=0;i<elements;i++){
if(arr[i]>value){
break;
}
}
for(int j=elements;j>i;j--){
arr[j] = arr[j-1];
}
arr[i] = value;
elements++;
}
/**
* 显示数据
*/
public void display(){
System.out.print("[");
for(int i=0;i<elements;i++){
System.out.print(" " +arr[i]+" ");
}
System.out.println("]");
}
/*
* 查找数据
*/
public int search(long value){
int i;
for(i=0;i<elements;i++){
if(value==arr[i]){
break;
}
}
if (i==elements){
return -1;
}else{
return i;
}
}
/*
* 二分法查找数据
*/
public int binarySearch(long value){
int middle = 0;
int low = 0;
int pow = elements;
while(true){
middle = (pow+low)/2;
if(arr[middle]==value){
return middle;
}else if(low>pow){
return -1;
}else{
if(arr[middle]>value){
pow = middle-1;
}else{
low = middle + 1;
}
}
}
}
/*
* 查找数据,根据索引来查
*/
public long get(int index){
if(index>=elements || index<0){
throw new ArrayIndexOutOfBoundsException();
}else{
return arr[index];
}
}
/*
* 删除数据
*/
public void delete(int index){
if(index>=elements || index<0){
throw new ArrayIndexOutOfBoundsException();
}else{
for(int i=index;i<elements;i++){
arr[index] = arr[index+1];
}
elements--;
}
}
/*
* 更新数据
*/
public void change(int index,int newvalue){
if(index>=elements || index<0){
throw new ArrayIndexOutOfBoundsException();
}else{
arr[index] = newvalue;
}
}
public static void main(String[] args) {
MyOrderArray arr = new MyOrderArray();
arr.insert(50);
arr.insert(20);
arr.insert(70);
arr.insert(60);
arr.display();
System.out.println(arr.binarySearch(80));
// System.out.println(arr.search(6));
// System.out.println(arr.get(3));
// arr.delete(0);
// arr.display();
// arr.change(0, 666);
// arr.display();
}
}