访问和修改2D动态分配的数组

#include <iostream>

int main() {
    int rows = 3;
    int cols = 4;

    // 动态分配二维数组
    int** array = new int*[rows];
    for (int i = 0; i < rows; ++i) {
        array[i] = new int[cols];
    }

    // 初始化数组
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            array[i][j] = i * cols + j;
        }
    }

    // 访问数组
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            std::cout << array[i][j] << " ";
        }
        std::cout << std::endl;
    }

    // 释放内存
    for (int i = 0; i < rows; ++i) {
        delete[] array[i];
    }
    delete[] array;

    return 0;
}

#include <iostream>

int main() {
    int rows = 3;
    int cols = 4;

    // 动态分配一维数组
    int* array = new int[rows * cols];

    // 初始化数组
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            array[i * cols + j] = i * cols + j;
        }
    }

    // 访问数组
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            std::cout << array[i * cols + j] << " ";
        }
        std::cout << std::endl;
    }

    // 释放内存
    delete[] array;

    return 0;
}

#include <iostream>

int main() {
    int rows = 3;
    int cols = 4;

    int** array = new int*[rows];
    for (int i = 0; i < rows; ++i) {
        array[i] = new int[cols];
    }

    // 初始化数组
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            array[i][j] = i * cols + j;
        }
    }

    // 访问数组并进行越界检查
    int row = 2;
    int col = 4;
    if (row >= 0 && row < rows && col >= 0 && col < cols) {
        std::cout << "Element at (" << row << ", " << col << ") is: " << array[row][col] << std::endl;
    } else {
        std::cout << "Out of bounds access!" << std::endl;
    }

    // 释放内存
    for (int i = 0; i < rows; ++i) {
        delete[] array[i];
    }
    delete[] array;

    return 0;
}