如何在C++中从函数返回矩阵(板)？

#include <iostream>

// 返回指向矩阵的指针
int** createMatrix(int rows, int cols) {
    int** matrix = new int*[rows];
    for (int i = 0; i < rows; ++i) {
        matrix[i] = new int[cols];
    }
    return matrix;
}

// 释放矩阵内存
void releaseMatrix(int** matrix, int rows) {
    for (int i = 0; i < rows; ++i) {
        delete[] matrix[i];
    }
    delete[] matrix;
}

int main() {
    int rows = 3;
    int cols = 3;
    int** matrix = createMatrix(rows, cols);

    // 使用矩阵
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] = i * cols + j;
            std::cout << matrix[i][j] << " ";
        }
        std::cout << std::endl;
    }

    // 释放矩阵内存
    releaseMatrix(matrix, rows);

    return 0;
}

#include <iostream>
#include <vector>

// 定义矩阵结构体
struct Matrix {
    std::vector<std::vector<int>> data;
    int rows;
    int cols;
};

// 创建矩阵
Matrix createMatrix(int rows, int cols) {
    Matrix matrix;
    matrix.rows = rows;
    matrix.cols = cols;
    matrix.data.resize(rows, std::vector<int>(cols));
    return matrix;
}

int main() {
    int rows = 3;
    int cols = 3;
    Matrix matrix = createMatrix(rows, cols);

    // 使用矩阵
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix.data[i][j] = i * cols + j;
            std::cout << matrix.data[i][j] << " ";
        }
        std::cout << std::endl;
    }

    return 0;
}

#include <iostream>
#include <vector>

// 定义矩阵类
class Matrix {
public:
    Matrix(int rows, int cols) : data(rows, std::vector<int>(cols)), rows(rows), cols(cols) {}

    // 获取矩阵元素
    int getElement(int row, int col) const {
        return data[row][col];
    }

    // 设置矩阵元素
    void setElement(int row, int col, int value) {
        data[row][col] = value;
    }

private:
    std::vector<std::vector<int>> data;
    int rows;
    int cols;
};

// 创建矩阵
Matrix createMatrix(int rows, int cols) {
    return Matrix(rows, cols);
}

int main() {
    int rows = 3;
    int cols = 3;
    Matrix matrix = createMatrix(rows, cols);

    // 使用矩阵
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix.setElement(i, j, i * cols + j);
            std::cout << matrix.getElement(i, j) << " ";
        }
        std::cout << std::endl;
    }

    return 0;
}