trie:141MS
#include<cstdio> const int maxn=100000+10; const int tk=26,tb=97; int triecnt=1,bufcnt=0,tree[maxn<<2][tk+1]; char buf[maxn<<1][12]; int search(char *s) { for(int rt=0;rt=tree[rt][*s-tb];) if(*(++s)==0) return tree[rt][tk]; return 0; } void insert(char *s,int rank=1) { int rt,nxt; for(rt=0;*s;rt=nxt,++s) { nxt=tree[rt][*s-tb]; if(!nxt) tree[rt][*s-tb]=nxt=triecnt++; } tree[rt][tk]=rank; } int main() { int i,j; char str[50]; while(gets(str)&&str[0]) { char *s1=buf[bufcnt],*s2=buf[bufcnt+1]; for(i=0;str[i]!=' ';i++) s1[i]=str[i]; s1[i]=0; while(str[++i]==' '); for(j=0;str[i];i++) s2[j++]=str[i]; s2[j]=0; insert(s2,bufcnt+1); bufcnt+=2; } while(gets(str)!=NULL) { int t=search(str); puts(t?buf[t-1]:"eh"); } return 0; }