1015. Reversible Primes (20) C#实现

 1 static void Main(string[] args)
 2         {
 3             string[] str;
 4             bool FLAG;
 5             int n = 0, d = 0;
 6             List<int> N = new List<int>();
 7             List<int> D = new List<int>();
 8
 9             do
10             {
11                 FLAG = true;
12                 str = Console.ReadLine().Split(new Char[] { ‘ ‘ });
13                 n = Convert.ToInt32(str[0]);
14
15                 if (n < 0)
16                 {
17                     FLAG = false;
18                 }
19                 else if (n > 100000)
20                 {
21                     Console.WriteLine("N>100000,请重输:");
22                 }
23                 else if (Convert.ToInt32(str[1]) <= 1 || Convert.ToInt32(str[1]) > 10)
24                 {
25                     Console.WriteLine("D值不在范围内，请重输：");
26                 }
27                 else
28                 {
29                     N.Add(Convert.ToInt32(str[0]));
30                     D.Add(Convert.ToInt32(str[1]));
31
32                 }
33             } while (FLAG == true);
34
35             for (int j = 0; j < D.Count; j++)
36             {
37                 if (Isprime(N[j]) && Isprime(Reverse(N[j], D[j])))
38                 {
39                     Console.WriteLine("YES");
40                 }
41                 else
42                 {
43                     Console.WriteLine("NO");
44                 }
45             }
46             Console.ReadKey();
47
48         }
49
50         public static int Reverse(int a, int d)
51         {
52             int sum = 0;
53             do
54             {
55                 sum = sum * d + a % d;
56                 a = a / d;
57             } while (a != 0);
58
59             return sum;
60         }
61
62         public static bool Isprime(int i)
63         {
64             if (i == 0 || i == 1)
65                 return false;
66             for (int p = 2; p < i / 2; p++)
67                 if (i % p == 0)
68                     return false;
69
70             return true;
71
72         }