POJ2503-Babelfish

http://poj.org/problem?id=2503

#include<iostream>
#include<string>
#include<map>
using namespace std;
map<string,string> rule;
int main(void)
{
    int cur,len;
    string s,s1,s2;
    while(getline(cin,s))
    {
        if((cur=s.find(' '))!=string::npos)
        {
            len=s.length();
            s1=s.substr(0,cur);
            s2=s.substr(cur+1,len);
            rule[s2]=s1;
        }
        else
        {
            if(s=="") 
               continue;
            if(rule[s]!="") 
               cout<<rule[s]<<endl;
            else 
               cout<<"eh\n";
        }
    }
    return 0;
}