Fill 2d array in spiral order in c

Question

I\'m doing program where I enter the number from keyboard. Then 2d array is created, and it\'s filled in spiral order till this number. All elements after the number will be equ

Answer 1

Try this:

void printArray(int array[10][10], int m, int n) {

    for (int i = 0; i < m; i++)
    {
        for (int j = 0; j < n; j++)
        {
            printf("%i\t", array[i][j]);
        }
        printf("\n");
    }
    printf("\n");
}

void spiral(int array[10][10], int m, int n, int s)
{
    int size, b, x = 0, y = 1, num = 1;
    size = m*n;
    while ( num <= s )
    {

        for (b = x; b < n; b++)
        {
            if (num <= s) {
                array[x][b] = num;
                num++;
            } else array[x][b] = 0;
        }

        if (num == size + 1)
        {
            break;
        }

        for (b = y; b < m; b++)
        {
            if (num <= s) {
                array[b][n - 1] = num;
                num++;
            } else array[b][n - 1] = 0;
        }

        if (num == size + 1)
        {
            break;
        }

        y++;
        n--;

        for (b = n - 1; b > x; b--)
        {
            if (num <= s) {
                array[m - 1][b] = num;
                num++;
            } else array[m - 1][b] = 0;
        }

        if (num == size + 1)
        {
            break;
        }


        for (b = m - 1; b > x; b--)
        {
            if (num <= s) {
                array[b][x] = num;
                num++;
            } else array[b][x] = 0;
        }
        x++; 
        m--;
    }
}



int main()
{
    int m, n, s, array[10][10];
    srand(time(NULL));
    m = 2 + rand() % 5;
    n = 2 + rand() % 5;
    memset(array, 0, sizeof(array[0][0]) * 10* 10);
    printf("enter the number \n");
    scanf("%i", &s);
    spiral(array, m, n, s);

    printArray(array, m, n);


    return (0);
}

Before you had some weird for loop on top of your spiral function. The num++ in it interfered with the fact that you already increased num by one and made it skip the number the next time it would write in the uppermost line. I changed it to a while loop that runs until num>s and it seems to work for me now.

Note that I just added printArray for easier debugging.