Java 根据优先级重新排列阵列
有Person类的对象,如:M1、M2、M3、M4、M5、W1、W2、W3、W4、C1、C2。其中M:男人,W:女人,C:孩子 它们存储在以下阵列中:Java 根据优先级重新排列阵列,java,arrays,sorting,Java,Arrays,Sorting,有Person类的对象,如:M1、M2、M3、M4、M5、W1、W2、W3、W4、C1、C2。其中M:男人,W:女人,C:孩子 它们存储在以下阵列中: Person[] arr = {M1,M3,C1,W1,W3,M2,M4,W2,C2,W4,M5}; 现在,必须根据为每种类型的对象设置的优先级重新排列数组。优先级在枚举中给出: enum Priority{ One, Two, Three; } 还要确保顺序保持不变,例如:M1应该在M2之前,M2应该在M3之前,等等
Person[] arr = {M1,M3,C1,W1,W3,M2,M4,W2,C2,W4,M5};
现在,必须根据为每种类型的对象设置的优先级重新排列数组。优先级在枚举中给出:
enum Priority{
One,
Two,
Three;
}
还要确保顺序保持不变,例如:M1应该在M2之前,M2应该在M3之前,等等
输入:Person[]arr={M1,M3,C1,W1,W3,M2,M4,W2,C2,W4,M5};
人类的优先权:优先权,二
女人的优先权:优先权。一
儿童优先:优先。三
预期产出:人员[]arr={W1、W2、W3、W4、M1、M2、M3、M4、M5、C1、C2}
输出不正确:Person[]arr={W1,W3,W2,W4,M1,M5,M4,M3,M2,C2,C1}
后者是错误的,因为顺序也必须保持不变。我认为您必须为Person类创建自己的比较器,以便可以使用Collections.sort方法在集合中对Person对象进行排序 下面是一个关于如何为类创建自己的比较器的链接
我认为您必须为Person类创建自己的comparator,以便可以使用Collections.sort方法在集合中对Person对象进行排序 下面是一个关于如何为类创建自己的比较器的链接
以下是使用Comparator接口对自定义对象进行排序的解决方案
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public class Person {
private int priority;
private String objName;
Person(String name,int value){
this.objName = name;
this.priority = value;
}
public int getPriority() {
return priority;
}
public void setPriority(int priority) {
this.priority = priority;
}
public String getObjName() {
return objName;
}
public void setObjName(String objName) {
this.objName = objName;
}
public static void main(String[] args) {
Person M1 = new Person("M1",Priority.valueOf("ONE").getValue());
Person M2 = new Person("M2",Priority.valueOf("ONE").getValue());
Person M3 = new Person("M3",Priority.valueOf("ONE").getValue());
Person M4 = new Person("M4",Priority.valueOf("ONE").getValue());
Person M5 = new Person("M5",Priority.valueOf("ONE").getValue());
Person W1 = new Person("W1",Priority.valueOf("THREE").getValue());
Person W2 = new Person("W2",Priority.valueOf("THREE").getValue());
Person W3 = new Person("W3",Priority.valueOf("THREE").getValue());
Person W4 = new Person("W4",Priority.valueOf("THREE").getValue());
Person C1 = new Person("C1",Priority.valueOf("TWO").getValue());
Person C2 = new Person("C2",Priority.valueOf("TWO").getValue());
Person[] arr = {M1,M3,C1,W1,W3,M2,M4,W2,C2,W4,M5};
List<Person> list = Arrays.asList(arr);
System.out.println("Before sort...");
for(Person p : list){
System.out.println(p.getObjName());
}
Collections.sort(list, new PersonComparator<Person>());
System.out.println("After sort...");
for(Person p : list){
System.out.println(p.getObjName());
}
}
}
enum Priority{
ONE(1),TWO(2),THREE(3);
private int value;
public int getValue() {
return value;
}
Priority(int v){
this.value = v;
}
}
class PersonComparator<T> implements Comparator<Person> {
public int compare(Person p1, Person p2) {
//Sorting based on priority
int v1 = p1.getPriority();
int v2 = p2.getPriority();
;
if (v1 - v2 == 0) {
//Sorting based on object name
int i1 = Integer.parseInt(p1.getObjName().substring(1, 2));
int i2 = Integer.parseInt(p2.getObjName().substring(1, 2));
return i1 - i2;
}
return v1 - v2;
}
}
下面是使用Comparator接口对自定义对象进行排序的解决方案
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public class Person {
private int priority;
private String objName;
Person(String name,int value){
this.objName = name;
this.priority = value;
}
public int getPriority() {
return priority;
}
public void setPriority(int priority) {
this.priority = priority;
}
public String getObjName() {
return objName;
}
public void setObjName(String objName) {
this.objName = objName;
}
public static void main(String[] args) {
Person M1 = new Person("M1",Priority.valueOf("ONE").getValue());
Person M2 = new Person("M2",Priority.valueOf("ONE").getValue());
Person M3 = new Person("M3",Priority.valueOf("ONE").getValue());
Person M4 = new Person("M4",Priority.valueOf("ONE").getValue());
Person M5 = new Person("M5",Priority.valueOf("ONE").getValue());
Person W1 = new Person("W1",Priority.valueOf("THREE").getValue());
Person W2 = new Person("W2",Priority.valueOf("THREE").getValue());
Person W3 = new Person("W3",Priority.valueOf("THREE").getValue());
Person W4 = new Person("W4",Priority.valueOf("THREE").getValue());
Person C1 = new Person("C1",Priority.valueOf("TWO").getValue());
Person C2 = new Person("C2",Priority.valueOf("TWO").getValue());
Person[] arr = {M1,M3,C1,W1,W3,M2,M4,W2,C2,W4,M5};
List<Person> list = Arrays.asList(arr);
System.out.println("Before sort...");
for(Person p : list){
System.out.println(p.getObjName());
}
Collections.sort(list, new PersonComparator<Person>());
System.out.println("After sort...");
for(Person p : list){
System.out.println(p.getObjName());
}
}
}
enum Priority{
ONE(1),TWO(2),THREE(3);
private int value;
public int getValue() {
return value;
}
Priority(int v){
this.value = v;
}
}
class PersonComparator<T> implements Comparator<Person> {
public int compare(Person p1, Person p2) {
//Sorting based on priority
int v1 = p1.getPriority();
int v2 = p2.getPriority();
;
if (v1 - v2 == 0) {
//Sorting based on object name
int i1 = Integer.parseInt(p1.getObjName().substring(1, 2));
int i2 = Integer.parseInt(p2.getObjName().substring(1, 2));
return i1 - i2;
}
return v1 - v2;
}
}
试试下面
final List<Person> persons = new ArrayList<>();
IntStream.rangeClosed(1, 5).mapToObj(i -> new Person("M" + i, Priority.TWO)).forEach(persons::add);
IntStream.rangeClosed(1, 4).mapToObj(i -> new Person("W" + i, Priority.ONE)).forEach(persons::add);
IntStream.rangeClosed(1, 2).mapToObj(i -> new Person("C" + i, Priority.THREE)).forEach(persons::add);
persons.add(new Person("M11", Priority.TWO)); // test to sort by number
List<Person> sorted = persons.stream()
.sorted(Comparator.comparing(Person::getPriority).thenComparingInt(p -> Integer.parseInt(p.getName().substring(1))))
.collect(Collectors.toList());
System.out.println("Before sort " + persons.stream().map(Person::getName).collect(Collectors.toList()));
System.out.println("After sort " + sorted.stream().map(Person::getName).collect(Collectors.toList()));
请注意:枚举中的值是有序的,上面的代码取决于枚举类中值的顺序
编辑-1
比较器
Comparator<Person> comp = new Comparator<Person>() {
@Override
public int compare(Person p1, Person p2) {
int co = p1.getPriority().compareTo(p2.getPriority());
if (co == 0)
return Integer.parseInt(p1.getName().substring(1)) - Integer.parseInt(p2.getName().substring(1));
return co;
}
};
试试下面
final List<Person> persons = new ArrayList<>();
IntStream.rangeClosed(1, 5).mapToObj(i -> new Person("M" + i, Priority.TWO)).forEach(persons::add);
IntStream.rangeClosed(1, 4).mapToObj(i -> new Person("W" + i, Priority.ONE)).forEach(persons::add);
IntStream.rangeClosed(1, 2).mapToObj(i -> new Person("C" + i, Priority.THREE)).forEach(persons::add);
persons.add(new Person("M11", Priority.TWO)); // test to sort by number
List<Person> sorted = persons.stream()
.sorted(Comparator.comparing(Person::getPriority).thenComparingInt(p -> Integer.parseInt(p.getName().substring(1))))
.collect(Collectors.toList());
System.out.println("Before sort " + persons.stream().map(Person::getName).collect(Collectors.toList()));
System.out.println("After sort " + sorted.stream().map(Person::getName).collect(Collectors.toList()));
请注意:枚举中的值是有序的,上面的代码取决于枚举类中值的顺序
编辑-1
比较器
Comparator<Person> comp = new Comparator<Person>() {
@Override
public int compare(Person p1, Person p2) {
int co = p1.getPriority().compareTo(p2.getPriority());
if (co == 0)
return Integer.parseInt(p1.getName().substring(1)) - Integer.parseInt(p2.getName().substring(1));
return co;
}
};
Saravana,我能不使用Stream做同样的事情吗。。我想说的是,我以前的解决方案是什么java8@RoyalTiger我已经添加了比较器,您可以在Collections.sort或Array.sortSaravana中使用它,我可以在不使用Stream的情况下使用它吗。。我想说的是,我以前的解决方案是什么java8@RoyalTiger我添加了Comparator,您可以在Collections.sort或Array中使用它。sortI无法以这种方式执行此操作。对象在数组中给定,不能修改Person类。只有Priority enum类包含每种类型对象的优先级。“你能建议其他的方法吗?”我很高兴,这有帮助。我不能用这种方法。对象在数组中给定,不能修改Person类。只有Priority enum类包含每种类型对象的优先级。“你能建议其他的方法吗?”我很高兴,这很有帮助。我已经改变了说法。它必须“重新排列”,而不是“排序”。我认为这个词有误导性。我已经重新措辞了这个声明。它必须“重新排列”,而不是“排序”。我认为这个词有误导性。