char* itos(int num)
{
	int len = 0, n = num, m = 0, s = 0, l = 0;
	while(n != 0){ n = n / 10; len ++; } n = num;
	char* buff = (char*)malloc(l = len);
	char* i = buff;

	do
	{
		s = n;
		n = n / 10;
		m = s - n * 10;
		*i++ = 0x30 + m;
	}while(--len>0);

	*i = 0;

	for(int j=0,k=l-1;j<l/2;j++,k--)
		buff[j] ^= buff[k] ^= buff[j] ^= buff[k];

	return buff;
}