#include <iostream>
#include <cmath>

void print_spiral (int ** matrix, int size);

int main()
{
	int ** matrix = new int * [4];
	for (int i=0; i<4; i++) matrix[i] = new int[4];
	
	// {  7,  8,  9, 10 },
	// {  6,  1,  2, 11 },
	// {  5,  4,  3, 12 },
	// { 16, 15, 14, 13 }
	
	matrix[0][0] = 7;  matrix[0][1] = 8;  matrix[0][2] = 9;  matrix[0][3] = 10;
	matrix[1][0] = 6;  matrix[1][1] = 1;  matrix[1][2] = 2;  matrix[1][3] = 11;
	matrix[2][0] = 5;  matrix[2][1] = 4;  matrix[2][2] = 3;  matrix[2][3] = 12;
	matrix[3][0] = 16; matrix[3][1] = 15; matrix[3][2] = 14; matrix[3][3] = 13;
	
	print_spiral(matrix, 4);
	
	return 0;
}

void print_spiral (int ** matrix, int size)
{
    int x = 0; // current position; x
    int y = 0; // current position; y
    int d = 0; // current direction; 0=RIGHT, 1=DOWN, 2=LEFT, 3=UP
    int c = 0; // counter
    int s = 1; // chain size
    
    // starting point
    x = ((int)floor(size/2.0))-1;
    y = ((int)floor(size/2.0))-1;
    
    for (int k=1; k<=(size-1); k++)
    {
        for (int j=0; j<(k<(size-1)?2:3); j++)
        {
            for (int i=0; i<s; i++)
            {
                std::cout << matrix[x][y] << " ";
                c++;
                
                switch (d)
                {
                    case 0: y = y + 1; break;
                    case 1: x = x + 1; break;
                    case 2: y = y - 1; break;
                    case 3: x = x - 1; break;
                }
            }
            d = (d+1)%4;
        }
        s = s + 1;
    }
}