poj1028 

很水，直接上代码吧。 


 1 #include<iostream>
 2 #include<string>
 3 #include<vector>
 4 
 5  using namespace std;
 6 
 7  
 8 
 9 int  main()
10 {
11  string now = "http://www.acm.org/";
12 
13  vector<string> back;
14  vector<string> forward;
15 
16  string tmp;
17 
18  while(1)
19  {
20   cin>>tmp;
21   if(tmp == string("QUIT"))
22   {
23    break;
24   }
25   if(tmp[0]=='V')
26   {
27    string url;
28    cin>>url;
29    back.push_back(now);
30    forward.clear();
31    now=url;
32    cout<<now<<endl;
33   }
34   else if(tmp[0]=='B')
35   {
36    if(!back.empty())
37    {
38     forward.push_back(now);
39     now = back.back();
40     cout<<now<<endl;
41     back.pop_back();
42    }
43    else
44    {
45     cout<<"Ignored"<<endl;
46    }
47   }
48   else
49   {
50    if(!forward.empty())
51    {
52     back.push_back(now);
53     now = forward.back();
54     cout<<now<<endl;
55     forward.pop_back();
56    }
57    else
58    {
59     cout<<"Ignored"<<endl;
60    }
61   }
62  }
63  return 0;
64 }
65 
66  
67

 

posted on 2010-10-23 20:43  Weifeng Wang  阅读(246)  评论(0)  编辑  收藏  举报

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