题目：输入数字n,按顺序打印出从1到最大的n为十进制数，比如输入3，则打印出1、2、3一直到最大的3位数即999 
代码：

//Recursively reslove
void Print1ToMaxOfNdigitalRecursively(char *number, int length, int index)
{
    if (index == length - 1)
    {
        printNum(number);
        return;
    }
    for (int i = 0; i < 10; i++)
    {
        number[index + 1] = '0' + i;
        Print1ToMaxOfNdigitalRecursively(number, length, index + 1);
    }

}
void SPrint1ToMaxOfNdigital(int n)
{
    if (n <= 0)
        return;

    char *number = (char *)malloc(sizeof(char) * (n +1));
    number[n] = '\0';

    for (int i = 0; i < 10; i++)
    {
        number[0] = i + '0';
        Print1ToMaxOfNdigitalRecursively(number, n, 0);
    }

    free(number);
}
void printNum(char *number)
{
    bool isBeginning0 = true;
    int nLength = strlen(number);

    for (int i = 0; i < nLength; i++)
    {
        if (isBeginning0 && number[i] != '0')
            isBeginning0 = false;

        if (!isBeginning0)
        {
            printf("%c", number[i]);
        }
    }
    printf("\t");
}