1113-Dsicover-The-Web.cpp

#include <iostream>
#include <stack>
#include <stdio.h>
using namespace std;

string choice;
int turn;

int nextturn()
{

		if(choice == "VISIT") {
			turn = 0;
		}

		if(choice == "FORWARD") {
			turn = 1;
		}

		if(choice == "BACK") {
			turn = 2;
		}

}

int main()
{
	ios_base::sync_with_stdio(false);
	
	int t;
	string url;
	stack <string> f;
	stack <string> b;

	cin >> t;

	for (int cs = 1; cs <= t; cs++) {
		cin >> choice;
		while(!b.empty()) {
			b.pop();
		}

		while(!f.empty()) {
			f.pop();
		}

		url = "http://www.lightoj.com/";
		cout << "Case "<<cs<<":\n";
		while(choice != "QUIT") {

			nextturn();
			switch(turn) {
	//vis for back
				case 0:
					b.push(url);
					cin >> url;
					cout << url << "\n";
					while(!f.empty()) {
						f.pop();
					}
					break;

				case 1:
					if(f.empty()) {
						cout << "Ignored\n";
					}

					else {
						b.push(url);
						url = f.top();
						f.pop();
						cout << url << "\n";
					}
					break;


				case 2:
					
					if(b.empty()) {
						cout << "Ignored\n";
					}

					else {
						f.push(url);
						url = b.top();
						b.pop();
						cout << url << "\n";
					}

					break;

			}


			cin >> choice;
		}



	}


}