优化这段代码使他能够用java运行
时间: 2024-03-03 19:49:13 浏览: 14
好的,这里是 Java 版本的实现:
```java
class Solution {
public int uniquePaths(int m, int n) {
int[][] dp = new int[m][n];
for (int i = 0; i < m; i++) {
dp[i][0] = 1;
}
for (int j = 0; j < n; j++) {
dp[0][j] = 1;
}
for (int i = 1; i < m; i++) {
for (int j = 1; j < n; j++) {
dp[i][j] = dp[i-1][j] + dp[i][j-1];
}
}
return dp[m-1][n-1];
}
}
```
这里需要注意的是,Java 中数组的下标是从 0 开始的,因此需要对边界条件进行一些修改。另外,Java 中的二维数组需要先指定行数再指定列数,因此定义二维数组时需要写成 `int[][] dp = new int[m][n]`。
相关问题
优化这段代码,加入多态,线程
好的,以下是优化后的代码,加入了多态和线程:
```java
public abstract class Insurance {
private String type;
private String coverage;
private double premium;
public Insurance(String type, String coverage, double premium) {
this.type = type;
this.coverage = coverage;
this.premium = premium;
}
public String getType() {
return type;
}
public String getCoverage() {
return coverage;
}
public double getPremium() {
return premium;
}
public void setType(String type) {
this.type = type;
}
public void setCoverage(String coverage) {
this.coverage = coverage;
}
public void setPremium(double premium) {
this.premium = premium;
}
public abstract void display();
public void calculatePremium() {
// 计算保费
System.out.println("Calculating premium...");
}
public void issuePolicy() {
// 发布保单
System.out.println("Issuing policy...");
}
}
public class HealthInsurance extends Insurance {
public HealthInsurance(String type, String coverage, double premium) {
super(type, coverage, premium);
}
@Override
public void display() {
System.out.println("Health Insurance:");
System.out.println("Type: " + getType());
System.out.println("Coverage: " + getCoverage());
System.out.println("Premium: $" + getPremium());
}
}
public class CarInsurance extends Insurance {
public CarInsurance(String type, String coverage, double premium) {
super(type, coverage, premium);
}
@Override
public void display() {
System.out.println("Car Insurance:");
System.out.println("Type: " + getType());
System.out.println("Coverage: " + getCoverage());
System.out.println("Premium: $" + getPremium());
}
}
public class InsuranceThread implements Runnable {
private Insurance insurance;
public InsuranceThread(Insurance insurance) {
this.insurance = insurance;
}
@Override
public void run() {
insurance.calculatePremium();
insurance.issuePolicy();
}
public static void main(String[] args) {
Insurance healthInsurance = new HealthInsurance("Health", "Medical expenses", 1000.00);
Insurance carInsurance = new CarInsurance("Car", "Accident damages", 500.00);
Thread healthThread = new Thread(new InsuranceThread(healthInsurance));
Thread carThread = new Thread(new InsuranceThread(carInsurance));
healthThread.start();
carThread.start();
}
}
```
在这个优化后的代码中,我们创建了一个抽象的 Insurance 类,它包含了保险类型、保险覆盖范围和保费等属性,以及一个抽象的 display() 方法用于显示保险介绍信息。同时,我们还加入了 calculatePremium() 和 issuePolicy() 方法,并使用多态实现了 HealthInsurance 和 CarInsurance 类,分别代表健康保险和车辆保险。
在 InsuranceThread 类中,我们使用了 Runnable 接口来实现多线程,以计算保费和发布保单。在 main() 方法中,我们创建了两个不同的保险对象,并使用两个线程分别计算保费和发布保单。通过这样的方式,我们可以提高程序的运行效率,同时实现了多态和线程的应用。
给这段代码优化一下并加上注释
下面是优化并添加注释的代码示例:
```java
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class PasswordDictionaryGenerator {
private static final String DICTIONARY_FILE_PATH = "password_dictionary.txt";
public static void main(String[] args) {
List<String> passwords = generatePasswords();
saveDictionary(passwords);
}
private static List<String> generatePasswords() {
List<String> passwords = new ArrayList<>();
// 生成密码的逻辑
String[] words = { "password", "123456", "admin", "qwerty" };
String[] numbers = { "123", "456", "789" };
// 将每个单词与每个数字组合生成密码
for (String word : words) {
for (String number : numbers) {
passwords.add(word + number);
passwords.add(number + word);
}
}
return passwords;
}
private static void saveDictionary(List<String> passwords) {
try (FileWriter writer = new FileWriter(DICTIONARY_FILE_PATH)) {
for (String password : passwords) {
writer.write(password);
writer.write(System.lineSeparator());
}
System.out.println("Password dictionary generated successfully!");
} catch (IOException e) {
System.out.println("An error occurred while saving the password dictionary.");
e.printStackTrace();
}
}
}
```
优化内容:
1. 将密码生成的逻辑进行了简化,只是示例代码,你可以根据需求进行修改。
2. 添加了注释,解释了代码的作用和实现细节。
3. 将生成的密码保存到 `password_dictionary.txt` 文件中。
4. 在保存字典文件时使用 `try-with-resources` 语句,确保文件资源被正确关闭。
5. 在发生异常时打印错误信息和堆栈跟踪,方便调试。
请注意,在运行此代码之前,请确保目标文件所在的目录是可写的,以及确认是否存在同名文件,以免覆盖已有的数据。