1 #include <iostream>
  2 #include <vector>
  3 using namespace std;
  4  
  5 int main()
  6 {
  7     int a;
  8     int b;
  9     vector<int> wei1;//
 
倒序存儲每一位
 10     vector<int> wei;//正序存儲每一位
 11     int tmp;
 12     int result1 = 0;
 13     int result2 = 0;
 14     while(cin>>a>>b)
 15     {
 16         int count=0;
 17         int num = 0;
 18         if(b <= 10)
 19             cout<<count<<endl;
 20         else
 21         {
 
 22             if(a<=10)
 23                 a = 11;
 24             for(int i=a;i<=b;i++)
 25             {
 26                 num=0;
 27                 tmp = i;
 28                 while(tmp)
 29                 {
 30                     wei1.push_back(tmp%10);
 31                     tmp = tmp/10;
 32                 }
 33                 for(int x=wei1.size()-1;x>=0;x--)
 34                 {
 35                     wei.push_back(wei1[x]);
 36                 }
 37                 
 38  
 39                 for(int k=0;k<wei.size();k++)
 40                 {
 41                     for(int z=k+1;z<wei.size();z++)
 42                     {
 43                         num = 0;//此處別忘了num置0
 44                         result1 = wei[k]*10+wei[z];
 45                         result2 = wei[z]*10+wei[k];
 46                         //判斷result是否為質數
 47                         if(result1/10 == 0)
 48                         {
 49                             result1 = 0;
 50                             num++;
 51                         }
 52  
 53                         for(int j=2;j<result1;j++)
 54                         {
 55                             if(result1%j==0)
 56                             {
 57                                 num++;
 58                             }
 59                         }
 60                         if(num == 0)
 61                         {
 62                             break;
 63                         }
 64  
 65                         else
 66                         {
 67                             num = 0;
 68                             if(result2/10 == 0)
 69                             {
 70                                 result2 = 0;
 71                                 num++;
 72                             }
 73  
 74                             for(int j=2;j<result2;j++)
 75                             {
 76                                 if(result2%j==0)
 77                                 {
 78                                     num++;
 79                                     break;
 80                                 }
 81                             }
 82                             if(num == 0)
 83                             {
 84                                 break;
 85                             }
 86                         }
 87                     }
 88  
 89                     if(num == 0)
 90                     {
 91                         count++;
 92                         break;
 93                     }
 94                 }
 95                 wei.clear();
 96                 wei1.clear();
 97             }
 98         }
 99         cout<<count<<endl;
100     }
101 }

神奇數--全國模擬（三）