边看边写(打印1到最大的n位数)

来源：互联网发布：javascript dom对象编辑：程序博客网时间：2024/06/05 02:40

注：之前写了使用大数打印的方法

C#代码

    #region 打印1到最大的n位数    /// <summary>    /// 输入数字n，按顺序打印出从1到最大的n位十进制数。比如输入3，则打印出1、2、3一直到最大的3位数即999。    /// 使用递归算法实现，以及使用字符排列的方式，如对000~999进行全排列。    /// </summary>    class MaxOfDigital    {        private int _n;        public int n         {            get { return _n; }            set { _n = value; }        }        public MaxOfDigital(int n)        { _n = n; }        public void PrintToMaxOfDigits()        {            if (n <= 0)            {                Console.WriteLine("n的值必须大于0！");                return;            }            List<char> number = new List<char>();            for (int i = 0; i < n; i++) number.Add('0');            for (int i = 0; i < 10; i++)            {                number[0] = Convert.ToChar(48+i);                PrintToMaxOfDigitsRecursiverly(number, n, 0);             }        }        private void PrintToMaxOfDigitsRecursiverly(List<char> number,int length,int index)        {            if (index == length - 1)             {                 PrintNumber(number);                return;            }            for (int i = 0; i < 10; i++)            {                number[index + 1] = Convert.ToChar(48+i);                PrintToMaxOfDigitsRecursiverly(number, length, index + 1);            }        }        public void PrintNumber(List<char> number)        {            number.ForEach(                delegate(char num)                {                    bool isBeginning0 = false;                    if (num == '0' && isBeginning0 == false)                    {                        isBeginning0 = true;                    }                    else                        Console.Write(num);                                     }              );            Console.Write(" ");        }    }    #endregion

C++代码

以下是《剑指Offer》的代码，printNumber函数简化了，

void PrintToMaxOfDigital(int n){if(n<=0)return;char *num = new char[n+1];num[n]='\0';for(int i =0 ;i<10;i++){num[0]= i+'0';PrintToMaxOfDigitalsRescursively(num,n,0);}delete []num;}void printNumber(char *num){copy(num,num+strlen(num),ostream_iterator<char,char>(cout,""));cout<<",";}void PrintToMaxOfDigitalsRescursively(char *num,int length,int index){if(index == length){printNumber(num);return;}for(int i=0;i<10;i++){num[index+1]= i+'0';PrintToMaxOfDigitalsRescursively(num,length,index+1);}}

对以上函数进行了简化、

void PrintToMaxOfDigital(int n){if(n<=0)return;char *num = new char[n+1];num[n]='\0';PrintToMaxOfDigitalsRescursively(num,n,0);delete []num;}void printNumber(char *num){copy(num,num+strlen(num),ostream_iterator<char,char>(cout,""));cout<<",";}void PrintToMaxOfDigitalsRescursively(char *num,int length,int index){if(index == length){printNumber(num);return;}for(int i=0;i<10;i++){num[index]= i+'0';PrintToMaxOfDigitalsRescursively(num,length,index+1);}}