sandpiles

Sandpiles

Resources

Read or watch:

Sandpiles - Numberphile

Requirements

• Allowed editors: vi, vim, emacs
• All your files will be compiled on Ubuntu 14.04 LTS
• Your programs and functions will be compiled with gcc 4.8.4 using the flags -Wall -Werror -Wextra and -pedantic
• All your files should end with a new line
• Your code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl
• You are not allowed to use global variables
• No more than 5 functions per file
• In the following examples, the main.c files are shown as examples. You can use them to test your functions, but you don’t have to push them to your repo (if you do we won’t take them into account). We will use our own main.c files at compilation. Our main.c files might be different from the one shown in the examples
• The prototypes of all your functions should be included in your header file called sandpiles.h
• Don’t forget to push your header file
• All your header files should be include guarded

---

0. Sandpiles sum

Write a function that computes the sum of two sandpiles

• Prototype: void sandpiles_sum(int grid1[3][3], int grid2[3][3]);
• You can assume that both grid1 and grid2 are individually stable
• A sandpile is considered stable when none of its cells contains more than 3 grains
• When your function is done, grid1 must be stable
• grid1 must be printed before each toppling round, only if it is unstable (See example)
• You’re not allowed to allocate memory dynamically

alex@~/0x04-sandpiles$ cat 0-main.c
#include <stdlib.h>
#include <stdio.h>

#include "sandpiles.h"

static void print_grid_sum(int grid1[3][3], int grid2[3][3])
{
	int i, j;

	for (i = 0; i < 3; i++)
	{
		for (j = 0; j < 3; j++)
		{
			if (j)
				printf(" ");
			printf("%d", grid1[i][j]);
		}

		printf(" %c ", (i == 1 ? '+' : ' '));

		for (j = 0; j < 3; j++)
		{
			if (j)
				printf(" ");
			printf("%d", grid2[i][j]);
		}
		printf("\n");
	}
}

static void print_grid(int grid[3][3])
{
	int i, j;

	for (i = 0; i < 3; i++)
	{
		for (j = 0; j < 3; j++)
		{
			if (j)
				printf(" ");
			printf("%d", grid[i][j]);
		}
		printf("\n");
	}
}

/**
* main - Entry point
*
* Return: EXIT_SUCCESS or EXIT_FAILURE
*/
int main(void)
{
	int grid1[3][3] = {
		{3, 3, 3},
		{3, 3, 3},
		{3, 3, 3}
	};
	int grid2[3][3] = {
		{1, 3, 1},
		{3, 3, 3},
		{1, 3, 1}
	};

	print_grid_sum(grid1, grid2);

	sandpiles_sum(grid1, grid2);

	printf("=\n");
	print_grid(grid1);

	return (EXIT_SUCCESS);
}
alex@~/0x04-sandpiles$ gcc -Wall -Wextra -Werror -pedantic 0-main.c 0-sandpiles.c -o 0-sandpiles
alex@~/0x04-sandpiles$ ./0-sandpiles
3 3 3   1 3 1
3 3 3 + 3 3 3
3 3 3   1 3 1
=
4 6 4
6 6 6
4 6 4
=
2 5 2
5 6 5
2 5 2
=
4 2 4
2 6 2
4 2 4
=
0 5 0
5 2 5
0 5 0
=
2 1 2
1 6 1
2 1 2
=
2 2 2
2 2 2
2 2 2
alex@~/0x04-sandpiles$ cat 1-main.c
Same as 0-main.c except:
int grid1[3][3] = {
        {0, 0, 0},
        {0, 0, 0},
        {0, 0, 0}
    };
    int grid2[3][3] = {
        {3, 3, 3},
        {3, 3, 3},
        {3, 3, 3}
    };
alex@~/0x04-sandpiles$ gcc -Wall -Wextra -Werror -pedantic 1-main.c 0-sandpiles.c -o 0-sandpiles
alex@~/0x04-sandpiles$ ./0-sandpiles
0 0 0   3 3 3
0 0 0 + 3 3 3
0 0 0   3 3 3
=
3 3 3
3 3 3
3 3 3
alex@~/0x04-sandpiles$

Repo:

GitHub repository: holbertonschool-interview

Directory: sandpiles

File: 0-sandpiles.c