剑指offer之打印1到最大的n位数

此题看上去很简单，但要考虑大数问题，所以采用定义一个char数组，如n为3，则定义一个number[4]就可以了，下面是一种算法，采用递归和非递归，递归是全排列算法。

#include
#include
using namespace std;

bool Increment(char* number);
void PrintNumber(char* number);
void Print1ToMaxOfN_2Recursively(char *number,int length,int index);
void text(int n);

void Print1ToMaxOfN_1(int n)
{
    if (n<=0) 
        throw 1;
    char *number=new char[n+1];
    memset(number,'0',n);
    number[n]='\0';

    while(!Increment(number))
    {
        PrintNumber(number);
    }

    delete []number;
}

bool Increment(char* number)
{
    int TakeOver=0;
    bool isOver=false;
    int length=strlen(number);
    for(int i=length-1;i>=0;i--)
    {
        int sum=number[i]-'0'+TakeOver;
        if(i==length-1)
            sum++;
        if(sum>=10)
        {
            if(i==0)
            {
                isOver=true;
                return isOver;
            }
            else
            {
                sum-=10;
                TakeOver=1;
                number[i]='0'+sum;
            }
        }
        else
        {
            number[i]='0'+sum;
            break;
        }
    }
    return isOver;
}

//递归实现 
void Print1ToMaxOfN_2(int n)
{
    if(n<=0)
        throw 1;
    char *number=new char[n+1];
    number[n]='\0';
    for(int i=0;i<10;i++)
    {
        number[0]=i+'0';
        Print1ToMaxOfN_2Recursively(number,n,0);
    }
    delete []number;
}

void Print1ToMaxOfN_2Recursively(char *number,int length,int index)
{
    if(index==length-1)
    {
        PrintNumber(number);
        return;
    }
    for(int i=0;i<10;i++)
    {
        number[index+1]=i+'0';
        Print1ToMaxOfN_2Recursively(number,length,index+1);
    }
}

//打印函数 
void PrintNumber(char* number)
{
    bool isBeginning0=true;
    int length=strlen(number);
    for(int i=0;iif(number[i]!='0'&&isBeginning0)
            isBeginning0=false;
        if(!isBeginning0)
            {
                cout<cout<<"  ";
}

void test(int n)
{
    try
    {
        cout<<"非递归解法"<cout<cout<<"递归解法"<cout<catch(...)
    {
        cout<<"n必须大于0";
    }
}
int main()
{
    test(1);
    test(2);
    test(3);
    test(-1);
    return 0;
}