View Code of Problem 163

#include<iostream>
#include<cmath>
#include<iomanip>
#include<cstring>
#include<string>
#include<vector>
#include<algorithm>
using namespace std;
int main()
{
	vector<string>a;
	vector<string>b;
	string s2 = "http://www.acm.org/";
	a.push_back(s2);
	string s;
	while (getline(cin, s))
	{
		if (s == "QUIT")
			break;
		if (s[0] == 'V')
		{
			string s1 = s.substr(6,s.size()-6);
			cout << s1<<endl;
			a.push_back(s1);
		}
		else if (s == "BACK")
		{
			
			if (a.size() > 1)
			{
				b.push_back(a[a.size() - 1]);
				a.pop_back();
				cout << a[a.size() - 1] << endl;
			}
			else
				cout << "Ignored" << endl;
		}
		else if (s == "FORWARD")
		{
			if (b.size() <=1)
				cout << "Ignored" << endl;
			else
			{
				cout << b[b.size() - 1] << endl;
				a.push_back(b[b.size() - 1]);
				b.pop_back();
			}
		}
	}

	
	
}