gistfile1.cpp

int _atoi(const _TCHAR *str)
{
	int num = 0;
	size_t i = 0;
	while(str[i] == ' ' || str[i] == '\r' || str[i] == '\n' || str[i] == '\t')
	{
		i++;
	}
	int minus = str[i]=='-' ? -1 : 1;
	if(str[i]=='-' || str[i]=='+')
	{
		i++;
	}
	while(iswdigit(str[i]))
	{
		num=num*10+(str[i++] - '0');
		if(num<0)
		{
			return minus == -1 ? INT_MIN : INT_MAX;
		}
	}

	return minus*num;
}