#define N 9

#include<stdio.h>
#define SEE 1
#define SAW 2
#if N < 1
#define N 1
#endif
int main(void)
{
	int i, j, next, dir = SEE, n = N - 1;
	int matrix[N][N];
	next = i = j = 0;
	while(N)
	{
		matrix[i][j] = ++next;
		if((i & j) == n) break;
		switch(dir)
		{
			case SEE:
				if(j == n)
				{
					++i; dir = SAW;
					break;
				}
				if(!i)
				{
					++j; dir = SAW;
					break;
				}
				--i; ++j;
			break;
			case SAW:
				if(i == n)
				{
					j++; dir = SEE;
					break;
				}
				if(!j)
				{
					i++; dir = SEE;
					break;
				}
				--j; ++i;
		}
	}
	printf("\n\nValue of N is %d.\n\n", N);
	for(i = 0; i <= n; ++i)
	{
		for(j = 0; j <= n; ++j)
			printf("\t%02d", matrix[i][j]);
		printf("\n\n");
	}
	return 0;
}