java

#include <iostream>  
#include <vector>  

class Array {
private:
    std::vector<std::vector<int>> matrix;
    int size;

public:
    // 构造函数  
    Array(int n) : size(n) {
        matrix.resize(n, std::vector<int>(n, 0));
    }

    // 设置矩阵元素  
    void setElement(int row, int col, int value) {
        if (row >= 0 && row < size && col >= 0 && col < size) {
            matrix[row][col] = value;
        }
        else {
            std::cerr << "Error: Index out of bounds!" << std::endl;
        }
    }

    // 获取矩阵元素  
    int getElement(int row, int col) const {
        if (row >= 0 && row < size && col >= 0 && col < size) {
            return matrix[row][col];
        }
        else {
            std::cerr << "Error: Index out of bounds!" << std::endl;
            return -1; // 返回-1表示错误  
        }
    }

    // 打印矩阵  
    void printMatrix() const {
        for (const auto& row : matrix) {
            for (int val : row) {
                std::cout << val << " ";
            }
            std::cout << std::endl;
        }
    }

    // 顺时针旋转90度  
    void rotate90Clockwise() {
        std::vector<std::vector<int>> rotatedMatrix(size, std::vector<int>(size, 0));
        for (int i = 0; i < size; ++i) {
            for (int j = 0; j < size; ++j) {
                rotatedMatrix[j][size - 1 - i] = matrix[i][j];
            }
        }
        matrix = rotatedMatrix;
    }
};

int main() {
    int n;
    std::cout << "Enter the size of the square matrix: ";
    std::cin >> n;

    Array arr(n);

    std::cout << "Enter the elements of the matrix row by row:" << std::endl;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            int value;
            std::cin >> value;
            arr.setElement(i, j, value);
        }
    }

    std::cout << "Original matrix:" << std::endl;
    arr.printMatrix();

    arr.rotate90Clockwise();

    std::cout << "Matrix after 90 degree clockwise rotation:" << std::endl;
    arr.printMatrix();

    return 0;
}