uva 759 - The Return of the Roman Empire

 #include <cstdio>
 #include <string>
 #include <map>
 using namespace std;

 const int SIZE = ;
 const int value[] = {, , , , , , , , , , , , };
 const string sign[] = {"I", "IV", "V", "IX", "X", "XL", "L", "XC", "C", "CD", "D", "CM", "M"};

 int main()
 {
     map<string, int> dic;
     for (int n = ; n < ; n++)
     {
         int num = n;
         string Roman = "";
         for(int i = SIZE - ; i >=  && num; i--)
         {
             while(num >= value[i])
             {
                 Roman += sign[i];
                 num -= value[i];
             }
         }
         dic[Roman] = n;
     }

     char s[];
     while(gets(s))
     {
         if(s[] == '\0')
         {
             puts("");
             continue;
         }
         if(dic.count(s)) printf("%d\n", dic[s]);
         else printf("This is not a valid number\n");
     }
     return ;
 }