C/C++ 二维数组

使用C语言用到了二维数组

 #include <iostream>
 #include <stdlib.h>
 using namespace std;

 void print_arr_fun1(int arr[][], int row){
     for (int i = ; i < row; ++i){
         for (int j = ; j < ; ++j)
             cout << arr[i][j] << " ";
         cout << endl;
     }
 }

 void print_arr_fun2(int *arr, int row, int col){
     for (int i = ; i < row; ++i){
         for (int j = ; j < col; ++j)
             cout << *(arr + i * row + j) << " ";
         cout << endl;
     }
 }

 void print_arr_fun3(int **arr, int row, int col){
     for (int i = ; i < row; ++i){
         for (int j = ; j < col; ++j)
             cout << arr[i][j] << " ";
         cout << endl;
     }
 }

 int main(){
     const int row = ;  //这里是const
     const int col = ;
     int arr1[row][col];
     for (int i = ; i < row; ++i)
         for (int j = ; j < col; ++j)
             arr1[i][j] = i * col + j;

     cout << "print_arr_fun1---------------------------" << endl;
     print_arr_fun1(arr1, row);
     cout << "print_arr_fun2---------------------------" << endl;
     print_arr_fun2((int*)arr1, row, col);

     cout << "print_arr_fun3---------------------------" << endl;
     int **arr2 = (int**)malloc(sizeof(int*) * row);
     //malloc
     for (int i = ; i < row; ++i)
         arr2[i] = (int*)malloc(sizeof(int) * col);
     for (int i = ; i < row; ++i)
         for (int j = ; j < col; ++j)
             arr2[i][j] = i * col + j;
     print_arr_fun3(arr2, row, col);

     //free
     for (int i = ; i < row; ++i)
         free(arr2[i]);
     free(arr2);

     return ;
 }

输出:

print_arr_fun1---------------------------
0 1 2
3 4 5
print_arr_fun2---------------------------
0 1 2
2 3 4
print_arr_fun3---------------------------
0 1 2
3 4 5