POJ 2685

 #include <iostream>
 #include <string>
 #define MAXN 26

 using namespace std;

 int _map[MAXN];

 string fun(int sum);

 int main()
 {
     //freopen("acm.acm","r",stdin);
     int test;
     int i;
     string s_1;
     string s_2;
     int sum_1;
     int sum_2;
     int sum;
     _map['m'-'a'] = ;
     _map['c'-'a'] = ;
     _map['x'-'a'] = ;
     _map['i'-'a'] = ;
     cin>>test;
     while(test --)
     {
         cin>>s_1>>s_2;
         sum_1 = ;
         sum_2 = ;
         for(i = ; i < s_1.length(); ++ i)
         {

             if(s_1[i] >= '' && s_1[i] <= '')
             {
                 ++ i;
                 sum_1 += (s_1[i-]-'')*_map[s_1[i]-'a'];
             }
             else
             {
                 sum_1 += _map[s_1[i]-'a'];
             }
         }
         for(i = ; i < s_2.length(); ++ i)
         {
             if(s_2[i] >= '' && s_2[i] <= '')
             {
                 ++ i;
                 sum_2 += (s_2[i-]-'')*_map[s_2[i]-'a'];
             }
             else
             {
                 sum_2 += _map[s_2[i]-'a'];
             }
         }
         //cout<<sum_1<<" "<<sum_2<<endl;
         sum = sum_1 + sum_2;
         cout<<fun(sum)<<endl;
     }
 }

 string fun(int sum)
 {
     string s;
     int num_m;
     int num_c;
     int num_x;
     int num_i;
     num_m = sum/;
     sum %= ;
     num_c = sum/;
     sum %= ;
     num_x = sum/;
     sum %= ;
     num_i = sum;
     if(num_m != )
     {
         if(num_m == )
         {
             s += 'm';
         }
         else
         {
             s += char(num_m + '');
             s += 'm';
         }
     }
     if(num_c != )
     {
         if(num_c == )
         {
             s += 'c';
         }
         else
         {
             s += char(num_c + '');
             s += 'c';
         }
     }

     if(num_x != )
     {
         if(num_x == )
         {
             s += 'x';
         }
         else
         {
             s += char(num_x + '');
             s += 'x';
         }
     }

     if(num_i != )
     {
         if(num_i == )
         {
             s += 'i';
         }
         else
         {
             s += char('' + num_i);
             s += 'i';
         }
     }
     return s;
 }