top button
Flag Notify
    Connect to us
      Facebook Login
      Site Registration Why to Join

Facebook Login
Site Registration

How to print element of 2d matrix in spiral?

+2 votes
566 views
How to print element of 2d matrix in spiral?
posted Oct 23, 2013 by Anuj Yadav

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button

3 Answers

+1 vote

See the following code

#define ROWS 5
#define COLS 5

int main()
{
    int arr[ROWS][COLS] =  {{ 1, 2, 3, 4, 17},
                            { 5, 6, 7, 8, 18},
                            { 9,10,11,12, 19},
                            {13,14,15,16, 20},
                            {21,22,23,24, 25}};

    // Four direction counters of current movement
    // Horizontal right, vertical bottom, horizontal left and vertical top respectively
    int hr, vb, hl, vt;

    // levl indicates current depth of our imaginary rectangle into array. Starting value is zero
    // since we are looping on the boundaries and ending value is the inner most rectangle
    int levl;
    for (levl=0; levl < COLS-levl; levl++)
    {
        for(hr=levl; hr < COLS-levl; hr++)   // go right
            printf("%d ,", arr[levl][hr]);

        for(vb=levl+1; vb < COLS-levl; vb++) // go down
            printf("%d ,", arr[vb][hr-1]);

        for(hl=vb-1; hl-1 >= levl; hl--)  // go left
            printf("%d ,", arr[vb-1][hl-1]);

        for(vt=vb-1; vt-1 > levl; vt--)  // go up
            printf("%d ,", arr[vt-1][hl]);
    }

    return 0;
}

Output

1 ,2 ,3 ,4 ,17 ,18 ,19 ,20 ,25 ,24 ,23 ,22 ,21 ,13 ,9 ,5 ,6 ,7 ,8 ,12 ,16 ,15 ,14 ,10 ,11 ,
answer Oct 23, 2013 by Luv Kumar
What is the complexity of this code ??
+1 vote
void main()
{
    int r;      // no of row
    int c;      //no of column
    int x;      
    int z;
    int l=0,n=0;
    int a[20][20];

    printf("Enter the row => ");
    scanf("%d",&r);
    printf("Enter the column => ");
    scanf("%d",&c);

    mat1(a,r,c,l,n,c*r);        //  This function will print matrix

    printf("\n MATRIX => \n");
    for(x=0;x<r;x++)
    {
        printf("\n\n\n");
        for(z=0;z<c;z++)
            printf("    %d",a[x][z]);
    }
    getch();
}


int mat1(int a[][20],int r,int c,int l,int n,int m)
{
    if(n<m)
    {
        int x,z;
        for(x=l;x<c;x++)
            a[l][x]=++n;
        for(z=l+1;z<r;z++)
            a[z][c-1]=++n;
        c--;
        mat2(a,r,c,l,n,m);
    }
    else
        return 1;
}

int mat2(int a[][20],int r,int c,int l,int n,int m)
{
    int x,z;
    if(n<m)
    {
        for(x=c-1;x>=l;x--)
            a[r-1][x]=++n;
        for(z=r-2;z>=l+1;z--)
            a[z][l]=++n;
        r--;
        l++;
        mat1(a,r,c,l,n,m);
    }
    else
        return 1;
}

complexity O(no of element in matrix).

answer Oct 24, 2013 by Vikas Upadhyay
0 votes

Thanks.

Assume 4*4

You have to walk as this, Row-Column[Forward] then Row-Column[Reverse]

  1. Ro ==> C0 to C2
    C3 ==> R0 to R2

  2. R3 ==> C3 to C1
    C0 ==> R3 to R1

With above you will be able to print outer layer. You have to increment all the value[ie index] by one and try for first inner later.

Hope this 2 steps will be unique and will work for N*N matrix also.

I let yo to write code for whole. Let me know if you find difficulties and let others also comment. with their ideas..

answer Oct 23, 2013 by sivanraj
Good Idea :)
Can you please write code too ??
Similar Questions
+6 votes
The input tree is as shown below
            40
            / \
        20      60
        / \       \
    10      30      80
      \            /  \ 
       15        70    90

Output: 15 30 60 80 90
+1 vote

C: Print the elements of a matrix in anti spiral order?

Input Matrix

1 2 3 
4 5 6 
7 8 9 

Output

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

1,1,2,2,2,6,6,6,7,7,7,7,7,7,7,8,8,9,9,9

Example:
Input = 1 Output=0 (First index of 1).
Input = 2 Output=2 (First index of 2).
Input = 6 Output= 5 (First index of 6).
Input = 7 Output= 8 (First index of 7).
Input = 8 Output=15 (First index of 8).
Input = 9 Output=17 (First index of 9).

+4 votes

Write a program to make AVL tree buy arranging element in array ?

Contact Us
+91 9880187415
sales@queryhome.net
support@queryhome.net
#280, 3rd floor, 5th Main
6th Sector, HSR Layout
Bangalore-560102
Karnataka INDIA.
QUERY HOME
...