POJ1028(AC).cpp

#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <fstream>
using namespace std;

int main()
{
	int top;
	int available;
	int i;
	int j;
	int t;
	string a[105];
	char cmd[1000];
	char head[20];
	char url[200];
	string urlstr;
	string headstr;
	//ofstream cout("out.txt");

	for(i = 0; i < 105; i++)
	{
		a[i] = "";
	}
	a[0] = "http://www.acm.org/";

	available = 1;
	top = 1;
	while(1)
	{
		gets(cmd);
		sscanf(cmd, "%s", head);
		headstr = head;
		if(headstr == "QUIT")
		{
			break;
		}
		else if(headstr == "BACK")
		{
			if(top <= 1)
			{
				cout<<"Ignored"<<endl;
			}
			else if(top > 1)
			{
				top--;
				cout<<a[top - 1]<<endl;
			}
		}
		else if(headstr == "FORWARD")
		{
			if(available > top)
			{
				cout<<a[top]<<endl;
				top++;
			}
			else
			{
				cout<<"Ignored"<<endl;
			}
		}
		else if(headstr == "VISIT")
		{
			strcpy(url, cmd + 6);
			urlstr = url;
			a[top] = url;
			cout<<a[top]<<endl;
			top++;
			if(available < top)
			{
				available = top;
			}
			else if(available > top)
			{
				available = top;
			}
		}
	}

	return 0;
}