冒泡
package com.bjsxt.sort.bubble;
import java.util.Arrays;
public class BubbleSort1 {
/**
* @param args
*/
public static void main(String[] args) {
int[] arr ={9,8,7,6,5};
sort(arr);
}
//第一版本，很简单
public static void sort(int[] arr){
int len =arr.length;
for(int j=0;j<len-1;j++){
System.out.println("第"+(j+1)+"趟");
for(int i=0;i<len-1;i++){
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
}
}
public static void sortSecond(int[] arr){
System.out.println("第一趟");
for(int i=0;i<arr.length-1;i++){
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
System.out.println("第二趟");
for(int i=0;i<arr.length-1;i++){
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
System.out.println("第三趟");
for(int i=0;i<arr.length-1;i++){
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
System.out.println("第四趟");
for(int i=0;i<arr.length-1;i++){
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
}
public static void sortFirst(int[] arr){
System.out.println("第一趟");
for(int i=0;i<arr.length-1;i++){
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
/*
//第一趟 第一次
System.out.println("第一趟 第一次");
int i=0;
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
System.out.println("第一趟 第二次");
i++;
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
System.out.println("第一趟 第三次");
i++;
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
System.out.println("第一趟 第四次");
i++;
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
*/
}
}
package com.bjsxt.sort.bubble;
import java.util.Arrays;
public class BubbleSort2 {
/**
* @param args
*/
public static void main(String[] args) {
int[] arr ={9,8,7,6,5};
sort(arr);
}
//第二版本，减少每一趟的次数
public static void sort(int[] arr){
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
System.out.println("第"+(j+1)+"趟");
for(int i=0;i<len-1-j;i++){ //次数
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
}
}
}
package com.bjsxt.sort.bubble; import java.util.Arrays; /**
* 最终版本：考虑存在顺序
* @author Administrator
*
*/
public class BubbleSort { /**
* @param args
*/
public static void main(String[] args) {
int[] arr ={1,2,9,3,4};
sort1(arr); System.out.println("==========final============");
arr =new int[]{9,1,2,3,4};
sortFinal(arr);
}
//第二版本，减少每一趟的次数
public static void sortFinal(int[] arr){
boolean sorted= true;
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
sorted =true; //假定有序
for(int i=0;i<len-1-j;i++){ //次数
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
sorted =false; //假定失败
}
System.out.println(Arrays.toString(arr));
}
if(sorted){ //减少趟数
break;
}
}
} //第二版本，减少每一趟的次数
public static void sort1(int[] arr){
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
System.out.println("第"+(j+1)+"趟");
for(int i=0;i<len-1-j;i++){ //次数
System.out.print("第"+(i+1)+"次");
if(arr[i]>arr[i+1]){
int temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
}
System.out.println(Arrays.toString(arr));
}
}
} }
引用数据类型：
1.整数小数Integer Float Double直接比较基本数据类型的大小
2.比较unicode码之差
3.字符串：
package com.bjsxt.sort.innerType;
/**
* 内置引用数据类型(常用)的比较
* @author Administrator
*
*/
public class Demo01 { /**
* @param args
*/
public static void main(String[] args) {
Integer a ; //根据基本数据类型大小
Character ch; //根据Unicode编码顺序
String str="abc"; //如果其中一个是例外一个起始开始的子串，返回长度之差
String str2 ="abcd123"; //否则返回第一个不相等的unicode码之差
System.out.println(str.compareTo(str2));
str ="abc";
str2 ="aad";
System.out.println(str.compareTo(str2)); java.util.Date d ; //根据日期的长整形数比较
} }
字符串的冒泡：
/**
* @param args
*/
public static void main(String[] args) {
String[] arr ={"a","abcd","abc","def"};
//从到小排序 降序
boolean sorted= true;
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
sorted =true; //假定有序
for(int i=0;i<len-1-j;i++){ //次数
if(((Comparable)arr[i]).compareTo(arr[i+1])<0){
String temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
sorted =false; //假定失败
}
}
if(sorted){ //减少趟数
break;
}
} System.out.println(Arrays.toString(arr));
}
时间的冒泡：
/**
* @param args
*/
public static void main(String[] args) {
Date[] arr =new Date[3];
arr[0] =new Date();
arr[1] =new Date(System.currentTimeMillis()-1000*60*60);
arr[2] =new Date(System.currentTimeMillis()+1000*60*60);
//降序 //从大到小排序 降序
boolean sorted= true;
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
sorted =true; //假定有序
for(int i=0;i<len-1-j;i++){ //次数
if(((Comparable)arr[i]).compareTo(arr[i+1])<0){
Date temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
sorted =false; //假定失败
}
}
if(sorted){ //减少趟数
break;
}
} System.out.println(Arrays.toString(arr));
}
封装+泛型之后：
package com.bjsxt.sort.innerType; import java.util.Comparator;
import java.util.List; /**
* 排序
* @author Administrator
*
*/
public class Utils {
/**
* List的排序+比较器
* @param list
* @param com
*/
public static <T> void sort(List<T> list,Comparator<T> com){
//第一步:转成数组
Object[] arr =list.toArray();
sort(arr,com);
//第二步:改变容器中对应的值
for(int i=0;i<arr.length;i++){
list.set(i, (T)(arr[i]));
}
} /**
* 数组的排序 （降序）+Comparator接口
* @param arr
*/
public static <T> void sort(Object[] arr,Comparator<T> com){
//从大到小排序 降序
boolean sorted= true;
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
sorted =true; //假定有序
for(int i=0;i<len-1-j;i++){ //次数
if(com.compare((T)arr[i], (T)arr[i+1])<0){
Object temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
sorted =false; //假定失败
}
}
if(sorted){ //减少趟数
break;
}
}
} /**
* 容器排序 (使用泛型方法)
*/
public static <T extends Comparable<T>> void sort(List<T> list){
//第一步:转成数组
Object[] arr =list.toArray();
sort(arr);
//第二步:改变容器中对应的值
for(int i=0;i<arr.length;i++){
list.set(i, (T)(arr[i]));
} } /**
* 数组排序 (使用泛型方法)
*/
public static <T extends Comparable<T>> void sort(T[] arr){
//从大到小排序 降序
boolean sorted= true;
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
sorted =true; //假定有序
for(int i=0;i<len-1-j;i++){ //次数
if(((Comparable)arr[i]).compareTo(arr[i+1])<0){
T temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
sorted =false; //假定失败
}
}
if(sorted){ //减少趟数
break;
}
}
} /**
* 数组的排序 （降序）
* @param arr
*/
public static void sort(Object[] arr){
//从大到小排序 降序
boolean sorted= true;
int len =arr.length;
for(int j=0;j<len-1;j++){ //趟数
sorted =true; //假定有序
for(int i=0;i<len-1-j;i++){ //次数
if(((Comparable)arr[i]).compareTo(arr[i+1])<0){
Object temp = arr[i];
arr[i] =arr[i+1];
arr[i+1] =temp;
sorted =false; //假定失败
}
}
if(sorted){ //减少趟数
break;
}
} } }
实例：
package com.bjsxt.sort.innerType; import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List; public class Demo04 { /**
* @param args
*/
public static void main(String[] args) {
Date[] arr =new Date[3];
arr[0] =new Date();
arr[1] =new Date(System.currentTimeMillis()-1000*60*60);
arr[2] =new Date(System.currentTimeMillis()+1000*60*60);
Utils.sort(arr); //降序
System.out.println(Arrays.toString(arr)); //字符串
String[] arr2 ={"a","abcd","abc","def"};
Utils.sort(arr2);
System.out.println(Arrays.toString(arr2)); System.out.println("==========List排序===========");
//存放容器中
List<String> list =new ArrayList<String>();
list.add("a");
list.add("abcd");
list.add("abc");
list.add("def");
Utils.sort(list);
System.out.println(list); System.out.println("==========使用Comparator 排序数组===============");
arr2 =new String[]{"a","abcd","abc","def"};
Utils.sort(arr2,new StringComp());
System.out.println(Arrays.toString(arr2)); System.out.println("==========List排序+比较器===========");
list =new ArrayList<String>();
list.add("a");
list.add("abcd");
list.add("abc");
list.add("def");
Utils.sort(list,new StringComp());
System.out.println(list); } }
方法而：实现java.util.Comparator接口
package com.bjsxt.sort.innerType;
/**
* 排序规则的业务类
* @author Administrator
*
*/
public class StringComp implements java.util.Comparator<String>{ /**
* 按长度比较大小
* 正数 >
* 负数 <
* 0 ==
*/
@Override
public int compare(String o1, String o2) {
int len1 =o1.length();
int len2 =o2.length();
return -(len1-len2);
} }
package com.bjsxt.sort.innerType; import java.util.ArrayList;
import java.util.Collections;
import java.util.List; /**
* 使用Collections对容器的比较
* 1、 public static <T> void sort(List<T> list, Comparator<? super T> c)
* 2、public static <T extends Comparable<? super T>> void sort(List<T> list)
* void sort(List<T> list)
* @author Administrator
*
*/
public class Demo05 { /**
* @param args
*/
public static void main(String[] args) {
List<String> list =new ArrayList<String>();
list.add("a");
list.add("abcd");
list.add("abc");
list.add("def");
Collections.sort(list,new StringComp());
System.out.println(list); list =new ArrayList<String>();
list.add("a");
list.add("abcd");
list.add("abc");
list.add("def");
Collections.sort(list);
System.out.println(list); } }
新闻条目的排序：
package com.bjsxt.sort.refType; import java.text.SimpleDateFormat;
import java.util.Date; /**
* 新闻条目实体类
* @author Administrator
*
*/
public class NewsItem implements java.lang.Comparable<NewsItem>{
//标题
private String title;
//点击量
private int hits;
//时间
private Date pubTime;
public NewsItem() {
} public NewsItem(String title, int hits, Date pubTime) {
super();
this.title = title;
this.hits = hits;
this.pubTime = pubTime;
} public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public int getHits() {
return hits;
}
public void setHits(int hits) {
this.hits = hits;
}
public Date getPubTime() {
return pubTime;
}
public void setPubTime(Date pubTime) {
this.pubTime = pubTime;
} //时间降序 +点击量升序+标题降序
@Override
public int compareTo(NewsItem o) {
int result =0;
//比较 时间
result =-this.pubTime.compareTo(o.pubTime); //降序
if(0==result){ //时间相同
//点击量
result =this.hits-o.hits; //升序
if(0==result){ //点击量相同
//标题
result=-this.title.compareTo(o.title);//降序
}
} return result;
} @Override
public String toString() {
StringBuilder sb =new StringBuilder();
sb.append("标题:").append(this.title);
sb.append(",时间:").append(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(this.pubTime));
sb.append(",点击量:").append(this.hits).append("\n");
return sb.toString();
} }
package com.bjsxt.sort.refType; import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List; import com.bjsxt.sort.innerType.Utils; /**
* 使用Collections
* @author Administrator
*
*/
public class NewsItemApp { /**
* @param args
*/
public static void main(String[] args) {
List<NewsItem> news=new ArrayList<NewsItem>();
news.add(new NewsItem("美国后怕了，逃跑了悲剧了",50,new Date(System.currentTimeMillis()-1000*60*60)));
news.add(new NewsItem("中国登上钓鱼岛了，全国欢呼了",100,new Date()));
news.add(new NewsItem("小日本终于听话了，泪流满面笑了",60,new Date(System.currentTimeMillis()-1000*60*60)));
System.out.println("排序前:"+news);
//排序
//Collections.sort(news);
Utils.sort(news);
System.out.println("排序后"+news); } }
商品的排序：
package com.bjsxt.sort.refType;
/**
* 实体类
* @author Administrator
*
*/
public class Goods {
//商品名称
private String name;
//价格
private double price;
//收藏量
private int fav;
public Goods() {
// TODO Auto-generated constructor stub
} public Goods(String name, double price, int fav) {
super();
this.name = name;
this.price = price;
this.fav = fav;
} public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public int getFav() {
return fav;
}
public void setFav(int fav) {
this.fav = fav;
} @Override
public String toString() {
return "商品名:"+name+",收藏量"+this.fav+",价格:"+this.price+"\n";
}
}
package com.bjsxt.sort.refType;
/**
* 按价格排序的业务类 （降序）
* @author Administrator
*
*/
public class GoodsPriceComp implements java.util.Comparator<Goods> { @Override
public int compare(Goods o1, Goods o2) {
return -(o1.getPrice()-o2.getPrice()>0?1:(o1.getPrice()==o2.getPrice()?0:-1));
} }
package com.bjsxt.sort.refType;
/**
* 按收藏量排序的业务类 （升序）
* @author Administrator
*
*/
public class GoodsFavComp implements java.util.Comparator<Goods> { @Override
public int compare(Goods o1, Goods o2) {
return o1.getFav()-o2.getFav();
} }
package com.bjsxt.sort.refType; import java.util.ArrayList;
import java.util.Collections;
import java.util.List; public class GoodsApp { /**
* @param args
*/
public static void main(String[] args) {
List<Goods> list =new ArrayList<Goods>();
list.add(new Goods("老马视频",100,2000));
list.add(new Goods("老高视频",50,2000));
list.add(new Goods("老裴视频",1000,1000));
System.out.println("排序前:"+list);
// Collections.sort(list,new GoodsPriceComp());
Collections.sort(list,new GoodsFavComp());
System.out.println("排序后:"+list);
} }
TreeSet：
注意：在添加数据是排序，数据更改不会影响原来的属性
package com.bjsxt.sort.col; import java.util.ArrayList;
import java.util.Collections;
import java.util.List; public class Person {
private final String name;//名称
private final int handsome;//帅气指数 public Person() {
name =null;
handsome =0;
} public Person(String name, int handsome) {
super();
this.name = name;
this.handsome = handsome;
} public String getName() {
return name;
} public int getHandsome() {
return handsome;
} @Override
public String toString() {
return "姓名:"+this.name+",帅气指数:"+this.handsome+"\n";
} }
package com.bjsxt.sort.col; import java.util.Set;
import java.util.TreeMap; public class TreeMapDemo { /**
* @param args
*/
public static void main(String[] args) {
Person p1 =new Person("您",100);
Person p2 =new Person("刘德华",1000);
Person p3 =new Person("梁朝伟",1200);
Person p4 =new Person("老裴",50); TreeMap<Person,String> map =new TreeMap<Person,String>(new java.util.Comparator<Person>(){ @Override
public int compare(Person o1, Person o2) {
return -(o1.getHandsome()-o2.getHandsome());
} } );
map.put(p1, "bjsxt");
map.put(p2, "bjsxt");
map.put(p3, "bjsxt");
map.put(p4, "bjsxt"); //查看键
Set<Person> persons =map.keySet();
System.out.println(persons);
} }
package com.bjsxt.sort.col;
public class Worker implements java.lang.Comparable<Worker> {
//工种
private String type;
//工资
private double salary;
public Worker() {
// TODO Auto-generated constructor stub
}
public Worker(String type, double salary) {
super();
this.type = type;
this.salary = salary;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
/**
* 按工资升序
*/
@Override
public int compareTo(Worker o) {
return this.salary>o.salary?1:( this.salary==o.salary?0:-1);
}
@Override
public String toString() {
return "工种:"+this.type+",工资:"+this.salary+"\n";
}
}
package com.bjsxt.sort.col; import java.util.TreeSet;
/**
* 实体类实现Comparable 接口的应用
* @author Administrator
*
*/
public class TreeSetDemo2 { /**
* @param args
*/
public static void main(String[] args) {
Worker w1 =new Worker("垃圾回收员",12000);
Worker w2 =new Worker("农民工",8000);
Worker w3 =new Worker("程序猿",5000); TreeSet<Worker> employees =new TreeSet<Worker>();
employees.add(w1);
employees.add(w2);
employees.add(w3);
System.out.println(employees); } }
TreeMap：
package com.bjsxt.sort.col; import java.util.Set;
import java.util.TreeMap; public class TreeMapDemo { /**
* @param args
*/
public static void main(String[] args) {
Person p1 =new Person("您",100);
Person p2 =new Person("刘德华",1000);
Person p3 =new Person("梁朝伟",1200);
Person p4 =new Person("老裴",50); TreeMap<Person,String> map =new TreeMap<Person,String>(new java.util.Comparator<Person>(){ @Override
public int compare(Person o1, Person o2) {
return -(o1.getHandsome()-o2.getHandsome());
} } );
map.put(p1, "bjsxt");
map.put(p2, "bjsxt");
map.put(p3, "bjsxt");
map.put(p4, "bjsxt"); //查看键
Set<Person> persons =map.keySet();
System.out.println(persons);
} }
package com.bjsxt.sort.col;
import java.util.TreeMap;
public class TreeMapDemo02 {
/**
* @param args
*/
public static void main(String[] args) {
Worker w1 =new Worker("垃圾回收员",12000);
Worker w2 =new Worker("农民工",8000);
Worker w3 =new Worker("程序猿",5000);
TreeMap<Worker,String > employees =new TreeMap<Worker,String >();
employees.put(w1,"bjsxt");
employees.put(w2,"bjsxt");
employees.put(w3,"bjsxt");
System.out.println(employees.keySet());
}
}
Collections 的相关方法：
package com.bjsxt.sort.util; import java.util.ArrayList;
import java.util.Collections;
import java.util.List; /**
*1、 binarySearch(List<? extends Comparable<? super T>> list, T key) 容器有序
*2、sort(List<T> list)
sort(List<T> list, Comparator<? super T> c)
*3、reverse(List<?> list)
4、shuffle(List<?> list) 洗牌
5、swap(List<?> list, int i, int j)
* @author Administrator
*
*/
public class CollectionsDemo01 { /**
* @param args
*/
public static void main(String[] args) {
List<Integer> cards =new ArrayList<Integer>();
//shuffle 洗牌 模拟斗地主
for(int i=0;i<54;i++){
cards.add(i);
}
//洗牌
Collections.shuffle(cards) ;
//依次发牌
List<Integer> p1 =new ArrayList<Integer>();
List<Integer> p2 =new ArrayList<Integer>();
List<Integer> p3 =new ArrayList<Integer>();
List<Integer> last =new ArrayList<Integer>();
for(int i=0;i<51;i+=3){
p1.add(cards.get(i));
p2.add(cards.get(i+1));
p3.add(cards.get(i+2));
}
//最后三张为底牌
last.add(cards.get(51));
last.add(cards.get(52));
last.add(cards.get(53)); System.out.println("第一个人:"+p1);
System.out.println("第二个人:"+p2);
System.out.println("第三个人:"+p3);
System.out.println("底牌为:"+last); }
//反转
public static void test1(){
List<Integer> list =new ArrayList<Integer>();
list.add(1);
list.add(2);
list.add(3);
list.add(4);
System.out.println(list);
Collections.reverse(list);
System.out.println("反转之后"+list);
}
}