fork download
copy 
  1. #include <stdlib.h>
  2. #include <stdio.h>
  3.  
  4. int main()
  5. {
  6.     int rows = 5, cols = 5;
  7.  
  8.     int ** board = (int **)malloc(rows * sizeof(int*)); //pointer to a table of pointers
  9.     //*board points to an array which stores addresses of the first column of each row
  10.     //board[0] = first row
  11.     //board[1] = second row
  12.     //board[0][0] =  first column of first row
  13.     //board[2][3] = 4th column of 3rd row
  14.  
  15.     board[0] = (int *)malloc(rows * cols * sizeof(int*)); //allocate memory for the whole board in one shot
  16.  
  17.     for(int i = 1; i < rows; i++)
  18.        board[i] = *board + cols*i; //set the table of pointers
  19.  
  20.    //testing code
  21.    //fill the first row with multiples of 1 (0, 1, 2, 3, 4)
  22.    //fill the second row with multiples of 2 (0, 2, 4, 6, 8)
  23.    //.
  24.    //.
  25.    //.
  26.    for(int i = 0; i < rows; i++)
  27.    		for(int j = 0; j < cols; j++)
  28.    		    board[i][j] = (i+1)*j;
  29.  
  30.     //printfs to check if the code is correct
  31.    	for(int i = 0; i < rows; i++)
  32.    	{
  33.    		for(int j = 0; j < cols; j++)
  34.    		    printf("%d ", board[i][j]);
  35.    		printf("\n");
  36.    	}
  37. }
Success #stdin #stdout 0s 16064KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
0 0 0 0 0 
0 1 2 3 4 
0 2 4 6 8 
0 3 6 9 12 
0 4 8 12 16
https://ideone.com/axi6aG
language:
C++ (gcc 8.3)
created:
8 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!