/*
 * ass12.c printing matrix in column-major, diagonal, anti-diagonal, 
 * anti-clockwise spiral order.
 */
#include <stdio.h>
#define ORD 20
int main()
{
    int n, i, j, k, l, h ;
    int data[ORD][ORD];
   
    printf("Enter the order of the square matrix: ");
    scanf("%d", &n);
    printf("Enter the matrix in row-major order:\n");
    for(i=0; i<n; ++i)
        for(j=0; j<n; ++j) scanf("%d", &data[i][j]);
    printf("The input matrix is:\n");
    for(i=0; i<n; ++i){
        for(j=0; j<n; ++j) printf("%d ", data[i][j]);
        putchar('\n');
    }

    printf("Elements in column-major order:\n"); 
    for(j=0; j<n; ++j)
        for(i=0; i<n; ++i)
            printf("%d ", data[i][j]);
    putchar('\n');

    printf("Elements in diagonal order:\n"); 
    for(i=n-1; i>=0; --i)
         for(j=0; i+j<n; ++j) printf("%d ", data[i+j][j]);
    for(i=1; i<n; ++i)
         for(j=i; j<n; ++j) printf("%d ", data[j-i][j]);
    putchar('\n');

    printf("Elements in diagonal order (2):\n"); 
    for(j=n-1; j>=0; --j)
         for(i=j; i<n; ++i) printf("%d ", data[i][i-j]);
    for(j=-1; j>-n; --j)
         for(i=-j; i<n; ++i) printf("%d ", data[j+i][i]);
    putchar('\n');

    printf("Elements in anti-diagonal order:\n"); 
    for(j=0; j<n; ++j)
        for(i=0; i<=j; ++i) printf("%d ", data[i][j-i]);
    k = 2*n-1;
    for(i=n; i<k; ++i)
        for(j=n-1; j >= i-n+1; --j) printf("%d ", data[i-j][j]);
    putchar('\n');

    printf("Elements in anticlockwise-spiral order:\n"); 
    for(l = 0, h = n-1; l < h; ++l, --h ) {
          for(i=l; i<h; ++i) printf("%d ", data[i][l]);
          for(i=l; i<h; ++i) printf("%d ", data[h][i]);
          for(i=h; i>l; --i) printf("%d ", data[i][h]);
          for(i=h; i>l; --i) printf("%d ", data[l][i]);
    }
    if(l == h) printf("%d ", data[l][l]); 
    putchar('\n');
   
    return 0;
}