如何在java或C++中生成给定2D矩阵的所有子矩阵？

public class SubMatrixGenerator {
    public static void generateSubMatrices(int[][] matrix) {
        int rows = matrix.length;
        int cols = matrix[0].length;

        for (int startRow = 0; startRow < rows; startRow++) {
            for (int startCol = 0; startCol < cols; startCol++) {
                for (int endRow = startRow; endRow < rows; endRow++) {
                    for (int endCol = startCol; endCol < cols; endCol++) {
                        printSubMatrix(matrix, startRow, startCol, endRow, endCol);
                    }
                }
            }
        }
    }

    public static void printSubMatrix(int[][] matrix, int startRow, int startCol, int endRow, int endCol) {
        for (int i = startRow; i <= endRow; i++) {
            for (int j = startCol; j <= endCol; j++) {
                System.out.print(matrix[i][j] + " ");
            }
            System.out.println();
        }
        System.out.println();
    }

    public static void main(String[] args) {
        int[][] matrix = {
            {1, 2, 3},
            {4, 5, 6},
            {7, 8, 9}
        };

        generateSubMatrices(matrix);
    }
}

#include <iostream>
using namespace std;

void generateSubMatrices(int matrix[][3], int rows, int cols) {
    for (int startRow = 0; startRow < rows; startRow++) {
        for (int startCol = 0; startCol < cols; startCol++) {
            for (int endRow = startRow; endRow < rows; endRow++) {
                for (int endCol = startCol; endCol < cols; endCol++) {
                    printSubMatrix(matrix, startRow, startCol, endRow, endCol);
                }
            }
        }
    }
}

void printSubMatrix(int matrix[][3], int startRow, int startCol, int endRow, int endCol) {
    for (int i = startRow; i <= endRow; i++) {
        for (int j = startCol; j <= endCol; j++) {
            cout << matrix[i][j] << " ";
        }
        cout << endl;
    }
    cout << endl;
}

int main() {
    int matrix[3][3] = {
        {1, 2, 3},
        {4, 5, 6},
        {7, 8, 9}
    };

    generateSubMatrices(matrix, 3, 3);

    return 0;
}