使用二分法的babelfish

#include<iostream>
#include<string.h>
#include<stdio.h>
#include<algorithm>
using namespace std;
const int mm=100010;
class node
{
public:
    char e[20],s[20];
}dic[mm];
char t[20];
int pos;
bool cmp(node a,node b)
{
    return strcmp(a.s,b.s)<0;
}
int binsearch(char *s)
{
    int l=0,r=pos-1;
    while(l<=r)
    {
        int mid = (l+r)/2;
        if(strcmp(dic[mid].s,s)==0)
            return mid;
        else if(strcmp(dic[mid].s,s)>0)
            r=mid-1;
        else
            l=mid+1;
    }
    return -1;
}
int main()
{
    pos=0;
    char z;
    while(scanf("%s%c",dic[pos].e,&z)!=EOF)
    {
        if(z=='\n')
        {
            strcpy(t,dic[pos].e);
            break;
        }
        cin>>dic[pos++].s;
    }
    sort(dic,dic+pos,cmp);
    int num = binsearch(t);
    if(num>=0)
        cout<<dic[num].e<<endl;
    else
        cout<<"eh"<<endl;
    while(cin>>t)
    {
        num = binsearch(t);
        if(num>=0)
            cout<<dic[num].e<<endl;
        else
            puts("eh");
    }
    return 0;
}