### Hello World 和 算法示例程序 #### C++ **Hello World** ```cpp #include <iostream> int main() { std::cout << "Hello, World!" << std::endl; return 0; } ``` **算法：求两个数的最大公约数 (Euclidean algorithm)** ```cpp #include <iostream> using namespace std; // Function to return gcd of a and b int gcd(int a, int b) { if (b == 0) return a; else return gcd(b, a % b); } int main() { int num1 = 56, num2 = 98; cout << "The GCD of " << num1 << " and " << num2 << " is " << gcd(num1, num2) << endl; return 0; } ``` *注：由于无法直接提供环境中的实时截图，建议你在本地IDE环境中编译并运行上述代码获取结果。* --- #### Java **Hello World** ```java public class HelloWorld { public static void main(String[] args) { System.out.println("Hello, World!"); } } ``` **算法：冒泡排序** ```java import java.util.Arrays; class BubbleSortExample { // A function to implement bubble sort static void bubbleSort(int arr[]) { int n = arr.length; for (int i = 0; i < n - 1; i++) for (int j = 0; j < n - i - 1; j++) if (arr[j] > arr[j + 1]) { // swap arr[j+1] and arr[j] int temp = arr[j]; arr[j] = arr[j + 1]; arr[j + 1] = temp; } } /* Prints the array */ static void printArray(int arr[]) { int n = arr.length; for (int i = 0; i < n; ++i) System.out.print(arr[i] + " "); System.out.println(); } // Driver method to test above public static void main(String args[]) { int arr[] = {64, 34, 25, 12, 22, 11, 90}; System.out.println("Sorted array"); bubbleSort(arr); printArray(arr); } } ``` 同样地，在自己的电脑上安装JDK并且通过命令行或者IDE工具如Eclipse、IntelliJ IDEA等去测试这个例子。 --- #### Python **Hello World** ```python print("Hello, World!") ``` **算法：斐波那契序列生成器** ```python def fibonacci(n): result = [] a, b = 0, 1 while len(result) < n: result.append(b) a, b = b, a + b return result # Print first 10 Fibonacci numbers. print(fibonacci(10)) ``` 可以直接将以上脚本保存成`.py`文件然后使用Python解释器来执行它，例如 `python script.py`. --- #### Rust **Hello World** ```rust fn main() { println!("Hello, world!"); } ``` **算法：查找列表中的最大值** ```rust fn find_max(list: &[isize]) -> Option<isize> { let mut largest = None; for &item in list.iter() { match largest { Some(current_largest) => { if item > current_largest { largest = Some(item); } }, None => largest = Some(item), } } largest } fn main() { let number_list = vec![34, 50, 25, 100, 65]; let max_value = find_max(&number_list); println!("Max value found: {:?}", max_value); } ``` 对于Rust来说，你需要先设置好Cargo项目结构，并且利用cargo run 来构建及运行应用程式的主函数。 --- 如果你需要进一步的帮助或有关于这些语言的具体疑问，请随时提问！