noip模拟赛 希望

#include <stack>
#include <string>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

string s, ss;
stack <string> s1, s2;
string q[1010];
int cnt = 1, maxx = 1;

int main()
{
    q[1] = "http://www.acm.org/";
    while (cin >> s && s != "QUIT")
    {
        if (s == "VISIT")
        {
            cin >> ss;
            q[++cnt] = ss;
            maxx = cnt;
            cout << ss << endl;
        }
        else
            if (s == "BACK")
            {
            if (cnt - 1 <= 0)
                printf("Ignored\n");
            else
            {
                cnt--;
                cout << q[cnt] << endl;
            }
            }
            else
            {
                if (cnt + 1 > maxx)
                    printf("Ignored\n");
                else
                {
                    cnt++;
                    cout << q[cnt] << endl;
                }
            }
    }
return 0;
}