Posted on 2008-03-27 22:28
superman 閱讀(218)
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1 /* Accepted 1061 C++ 00:00.05 856K */
2 #include <stack>
3 #include <string>
4 #include <iostream>
5
6 using namespace std;
7
8 int main()
9 {
10 int n;
11 cin >> n;
12 while(n--)
13 {
14 string command, url, curURL = "http://www.acm.org/";
15 stack<string> backward, forward;
16
17 while(1)
18 {
19 cin >> command;
20 if(command == "QUIT")
21 break;
22 if(command == "VISIT")
23 {
24 backward.push(curURL);
25 cin >> curURL;
26 while(forward.empty() == false)
27 forward.pop();
28 }
29 if(command == "BACK")
30 {
31 if(backward.empty())
32 {
33 cout << "Ignored" << endl;
34 continue;
35 }
36 else
37 {
38 forward.push(curURL);
39 curURL = backward.top();
40 backward.pop();
41 }
42 }
43 if(command == "FORWARD")
44 {
45 if(forward.empty())
46 {
47 cout << "Ignored" << endl;
48 continue;
49 }
50 else
51 {
52 backward.push(curURL);
53 curURL = forward.top();
54 forward.pop();
55 }
56 }
57 cout << curURL << endl;
58 }
59 if(n)
60 cout << endl;
61 }
62
63 return 0;
64 }
65