剑指Offer10 打印1到最大n位数

  1 /*************************************************************************
  2     > File Name: 10_PrintToMaxNum.c
  3     > Author: Juntaran
  4     > Mail: JuntaranMail@gmail.com
  5     > Created Time: 2016年08月30日 星期二 00时47分36秒
  6  ************************************************************************/
  7 
  8 #include <stdio.h>
  9 #include <malloc.h>
 10 #include <string.h>
 11 
 12 
 13 void PrintNumber(char* number)
 14 {
 15     bool isBeginning0 = true;
 16     int length = strlen(number);
 17     
 18     for (int i = 0; i < length; ++i)
 19     {
 20         if (isBeginning0 && number[i]!=‘0‘)
 21             isBeginning0 = false;
 22         
 23         if (!isBeginning0)
 24             printf("%c", number[i]);
 25     }
 26     printf("\t");
 27 }
 28 
 29 
 30 bool Increment(char* number)
 31 {
 32     bool isOverflow = false;
 33     int length = strlen(number);
 34     int TakeOver = 0;
 35     
 36     for (int i = length-1; i >= 0; i--)
 37     {
 38         int sum = number[i] - ‘0‘ + TakeOver;    // 进位
 39         if (i == length - 1)
 40             sum ++;
 41         
 42         if (sum >= 10)
 43         {
 44             if (i == 0)
 45                 isOverflow = true;
 46             else
 47             {
 48                 sum -= 10;
 49                 TakeOver = 1;
 50                 number[i] = sum + ‘0‘;
 51             }
 52         }
 53         else
 54         {
 55             number[i] = sum + ‘0‘;
 56             break;
 57         }
 58     }
 59     return isOverflow;
 60 }
 61 
 62 // 从1打印到最大的n位数
 63 void PrintToMaxNum1(int n)
 64 {
 65     if (n <= 0)
 66         return;
 67     
 68     char* number = (char*)malloc(sizeof(char)*(n+1));
 69     memset(number, ‘0‘, n);
 70     number[n] = ‘\0‘;
 71     
 72     while (!Increment(number))
 73     {
 74         PrintNumber(number);
 75     }
 76     free(number);
 77 }
 78 
 79 
 80 /************************************************************************/
 81 // 递归写法
 82 void PrintToMaxNumRecursively(char* number, int length, int index)
 83 {
 84     if (index == length-1)
 85     {
 86         PrintNumber(number);
 87         return;
 88     }
 89     for (int i = 0; i < 10; ++i)
 90     {
 91         number[index+1] = i + ‘0‘;
 92         PrintToMaxNumRecursively(number, length, index+1);
 93     }
 94 }
 95 
 96 void PrintToMaxNum2(int n)
 97 {
 98     if (n <= 0)
 99         return;
100     
101     char* number = (char*)malloc(sizeof(char)*(n+1));
102     number[n] = ‘\0‘;
103     
104     for (int i = 0; i < 10; ++i)
105     {
106         number[0] = i + ‘0‘;
107         PrintToMaxNumRecursively(number, n, 0);
108     }
109     free(number);
110 }
111 
112 
113 int main()
114 {
115     int n = 5;
116     PrintToMaxNum1(n);
117     PrintToMaxNum2(n);
118 }