Thread: 3 dimentional arrays

how can i do this

Code:

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int test[3][3][9] = { 0 };

    for ( int i = 0; i < 3; i++ )
        for ( int j = 0; j < 3; j++ )
            for ( int z = 0; z < 9; z++ )
                test[i][j][z] = z + 1;

    int counter = 1;
    for ( int i = 0; i < 3; i++ )
        for ( int j = 0; j < 3; j++ )
        {
            test[i][j] = counter;
            counter++;
        }

    for ( int i = 0; i < 3; i++ )
        for ( int j = 0; j < 3; j++ )
        {
            for ( int z = 0; z < 9; z++ )
                printf("i = %d j = %d z = %d element = %d\n", i, j, z, test[i][j][z]);
        putchar('\n');
        }

    return 0;
}

i need to make a suduko grid im trying to put the solved squares in co-ordinates i and j and the possible values in z

Please stop "initializing" your arrays with

Code:

= {0}

when there is no need to.
Sometimes it is useful, often it is not. With your strings it is often covering up mistakes (not properly zero-terminating them in your functions).

Anyway, obviously you can't do this:

Code:

            test[i][j] = counter;

test[i][j] is an array of 9 ints.
test[i][j][k] is an int.
I can't tell what you are trying to do so I can't fix it.

I understand the basic idea. I just have no idea what the loop starting at line 14 is supposed to be doing. You've already filled the 3x3 grid of 9-ints with the numbers 1 to 9 in the previous triple loop.
BTW, it's spelled sudoku.
And "dimension" is has an 's', not a 't'.

It is not possible to assign a value to test[i][j]. It is meaningless. You seem very confused as to how arrays work.
test is an array of 3 arrays of 3 arrays of 9 ints.
test[i] is an array of 3 arrays of 9 ints.
test[i][j] is an array of 9 ints.
test[i][j][k] is an int.
There is a total of 3 * 3 * 9 = 81 ints in test.

Also, sudoku boards are 9 x 9, divided into 3x3 3x3 grids.
Sudoku - Wikipedia

Sudoku boards are 9x9.
Sudoku - Wikipedia

Example board:

Code:

5 - -   - 1 6   2 - -
- - -   9 8 -   5 - 4
- 3 -   - - -   - - 9

- - -   6 - -   1 - -
9 - 6   - - -   - - 2
- 2 3   - 4 9   - - -

- 4 -   - - -   - 8 1
3 1 5   2 9 -   - 6 7
8 - 9   4 7 1   - 2 5

I'll leave you to it then.

Not at all. There's just nothing for me to do here. You seem to have it in hand. Give it a go.

I just whipped up a simplistic solver in < 10 minutes that solves that grid I posted.
I did not need lists of numbers. I just tried them all in a 9x9 grid.
This simplistic program would be pretty useless on a difficult grid, though, so maybe your number lists will help.
IIRC, expert solvers are quite complicated.

Code:

5 9 4   3 1 6   2 7 8 
6 7 1   9 8 2   5 3 4 
2 3 8   7 5 4   6 1 9 

4 8 7   6 2 5   1 9 3 
9 5 6   1 3 7   8 4 2 
1 2 3   8 4 9   7 5 6 

7 4 2   5 6 3   9 8 1 
3 1 5   2 9 8   4 6 7 
8 6 9   4 7 1   3 2 5

Some symbolic constants, and slightly better loop variable names would go a long way to understanding.

Code:

#include <stdio.h>

// The dimensions of the smaller square
#define REGION_W    3
#define REGION_H    3

// The dimensions of the larger square, number of regions
#define SQUARE_W    3
#define SQUARE_H    3

int main(void) {
    int game[SQUARE_H][SQUARE_W][REGION_H][REGION_W];

    for ( int sh = 0 ; sh < SQUARE_H ; sh++ ) {
        for ( int sw = 0 ; sw < SQUARE_W ; sw++ ) {
            for ( int rh = 0 ; rh < REGION_H ; rh++ ) {
                for ( int rw = 0 ; rw < REGION_W ; rw++ ) {
                    game[sh][sw][rh][rw] = rh * 3 + rw + 1;
                }
            }
        }
    }

    // now print the whole board.
    // note how the loops are rearranged!
    printf("-------------------------\n");
    for ( int sh = 0 ; sh < SQUARE_H ; sh++ ) {
        for ( int rh = 0 ; rh < REGION_H ; rh++ ) {
            printf("| ");
            for ( int sw = 0 ; sw < SQUARE_W ; sw++ ) {
                for ( int rw = 0 ; rw < REGION_W ; rw++ ) {
                    printf("%d ", game[sh][sw][rh][rw]);
                }
                printf("| ");
            }
            printf("\n");
        }
        printf("-------------------------\n");
    }

    return 0;
}


$ ./a.out 
-------------------------
| 1 2 3 | 1 2 3 | 1 2 3 | 
| 4 5 6 | 4 5 6 | 4 5 6 | 
| 7 8 9 | 7 8 9 | 7 8 9 | 
-------------------------
| 1 2 3 | 1 2 3 | 1 2 3 | 
| 4 5 6 | 4 5 6 | 4 5 6 | 
| 7 8 9 | 7 8 9 | 7 8 9 | 
-------------------------
| 1 2 3 | 1 2 3 | 1 2 3 | 
| 4 5 6 | 4 5 6 | 4 5 6 | 
| 7 8 9 | 7 8 9 | 7 8 9 | 
-------------------------

The loops might be in different orders, but the subscripts are always in the same order.