ACM: Web Navigation - c++

Question

Note:This problem I wrote is just for the people who know about ACM questions.
I have problem with this question. I wrote a good solution for this but every time I send it I get Wrong Answer. I don't know what's wrong here. I test this code for lots of test cases. Can you help me to fix my code?
Here is the link of the question: http://sharecode.ir/section/problemset/problem/1022.
Here is my code :
#include <iostream>
#include <vector>
#include <string>
using namespace std;
int main()
{
int n;
cin >> n;
while (n--)
{
string page[1000] = { "" };
int cntr = 0;
page[cntr] = "http://www.acm.org/";
string page1;
while (1)
{
cin >> page1;
if (page1 == "QUIT")
break;
if (page1 == "VISIT")
{
cntr++;
cin >> page1;
page[cntr] = page1;
cout << page1 << endl;
}
if (page1 == "BACK")
{
cntr--;
if (cntr >= 0)
cout << page[cntr] << endl;
else
{
cout << "Ignored" << endl;
cntr = 0;
}
}
if (page1 == "FORWARD")
{
cntr++;
if (page[cntr] == "")
cout << "Ignored" << endl;
else
cout << page[cntr] << endl;
}
}
if (n) cout << endl;
}
}

Answer 1

You don't clear forwards after visiting a site. That's why you get wrong answer.
Here is the correct code:
#include <iostream>
#include <vector>
#include <string>
using namespace std;
int main(int n){
cin >> n;
while (n--){
string c;
vector <string> a(999,"\0");
a[0] = "http://www.acm.org/";
int i = 0;
while(cin>>c,c != "QUIT"){
if (c == "VISIT"){
i++;
string s;
cin >> s;
a[i] = s;
cout << a[i] << "\n";
int t = i+1;
while (a[t] != "\0") {
a[t] = "\0";
t++;
}
}
if (c == "BACK"){
i--;
if (i < 0) {cout << "Ignored\n"; i=0;} else cout << a[i] << "\n";
}
if (c == "FORWARD"){
i++;
if (a[i] == "\0") {cout << "Ignored\n"; i--;} else cout << a[i] << "\n";
}
}
if (n) cout << "\n";
}
}