hdu 1181

import java.util.ArrayDeque;import java.util.ArrayList;import java.util.Queue;import java.util.Scanner;public class Main{static ArrayList<String> a=new ArrayList<String>();static Queue<String> b=new ArrayDeque<String>();public static void main(String[] args){     Scanner input=new Scanner(System.in);while(input.hasNext()){   String s;   while(!(s=input.next()).equals("0")){       if(s.charAt(0)=='b'){      b.add(s);   }       else  a.add(s);   }   System.out.println(F());   a.clear();   b.clear();}}private static String F(){    while(!b.isEmpty()){    String s=b.poll();char ch=s.charAt(s.length()-1);if(ch=='m')return "Yes.";for(int i=0;i<a.size();){    if(a.get(i).charAt(0)==ch){   b.add(a.remove(i));}elsei++;}}return "No.";}}

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1181