数学小工具：
package com.example;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class App {
// 计算阶乘
public static long factorial(int n) {if (n < 0) {throw new IllegalArgumentException("阶乘只能计算非负整数");}long result = 1;for (int i = 2; i <= n; i++) {result *= i;}return result;
}// 判断质数
public static boolean isPrime(int n) {if (n <= 1) {return false;}for (int i = 2; i * i <= n; i++) {if (n % i == 0) {return false;}}return true;
}// 合并两个列表并去重
public static List<Integer> mergeAndDistinct(List<Integer> list1, List<Integer> list2) {Set<Integer> set = new HashSet<>(list1);set.addAll(list2);return new ArrayList<>(set);
}// 查找列表中的最大值
public static int findMax(List<Integer> list) {if (list == null || list.isEmpty()) {throw new IllegalArgumentException("列表不能为空");}int max = list.get(0);for (int num : list) {if (num > max) {max = num;}}return max;
}public static void main(String[] args) {// 测试阶乘System.out.println("5 的阶乘是: " + factorial(5));// 测试质数判断System.out.println("7 是否是质数: " + isPrime(7));System.out.println("10 是否是质数: " + isPrime(10));// 测试合并列表并去重List<Integer> list1 = List.of(1, 2, 3, 4);List<Integer> list2 = List.of(3, 4, 5, 6);List<Integer> mergedList = mergeAndDistinct(list1, list2);System.out.println("合并后的列表: " + mergedList);// 测试查找最大值System.out.println("列表中的最大值: " + findMax(mergedList));
}
}
