POJ2503-Babelfish-二分

#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;

struct node{
    char s1[25],s2[25];
}a[N];

int n;

int cmp(node a,node b){
    return strcmp(a.s2,b.s2)<0;                    //感觉好厉害(；′д｀)ゞ
}

int main(){
    n=0;
    char str[50];
    while(gets(str)){
        if(str[0]==‘\0‘) break;
        sscanf(str,"%s%s",a[n].s1,a[n].s2);        //好厉害(；′д｀)ゞ
        n++;
    }
    sort(a,a+n,cmp);
    while(gets(str)){
       int l=0,r=n,mid,flag=1;
       while(l<=r){                                //二分
        mid=(l+r)>>1;
        if(strcmp(str,a[mid].s2)==0){
           printf("%s\n",a[mid].s1);
           flag=0;
           break;
        }
        else if(strcmp(str,a[mid].s2)<0)
            r=mid-1;
        else
            l=mid+1;
       }
       if(flag)
        printf("eh\n");
    }
    return 0;
}