sicily--1509. Rails

用棧模擬不難

// Problem#: 1509
// Submission#: 878974
// The source code is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
// URI: http://creativecommons.org/licenses/by-nc-sa/3.0/
// All Copyright reserved by Informatic Lab of Sun Yat-sen University
#include <iostream>
#include <stack>
#include <vector>
using namespace std;

int main()
{
    
    int coach_num;                                  //車廂的數目
    while( cin >> coach_num && coach_num != 0 )     //車廂數目爲0將不會操作
    {       
        int test;   
        while(cin >> test && test != 0)
        {
            vector<int> coach_out;                          //coach_out記錄用戶希望出站的車廂順序
            vector<int>::iterator it;
            stack<int> coach_in;                            //coach_in用於在站內可以出站的車廂的順序
            int coach_counter = 0;                          //記錄已出站的車廂數目
            for( int i = 1; i <= coach_num; ++i )       //coach_out記錄用戶希望出站的車廂順序
            {                                           
                int temp;
                if( i == 1 )
                    coach_out.push_back(test);
                else
                {
                    cin >> temp;
                    coach_out.push_back(temp);
                }
            
            }
            
            it = coach_out.begin();
        
            for( int j = 1; j <= coach_num; ++j)      //如果將要入站的標號與用戶希望出站的標號相同，則出站
            {                                         //j用於表示入站的順序
                if( j == (*it))                       //如果將要入站的車廂與用戶希望接下來要出站的車廂編號一致，則將此車廂出站
                {
                    it = coach_out.erase(it);
                    coach_counter++;                   //標記出站的車廂數目加1
                }
                else                                  //如果來到的車廂不是用戶想要出站的就先入站
                {
                    while( !coach_in.empty() && coach_in.top() == (*it))
                    {
                        it= coach_out.erase(it);
                        coach_counter++;
                        coach_in.pop();
                    }
                    coach_in.push(j);
                }
            }
            
            if(coach_out.empty())
                ;
            else
                for(it = coach_out.begin(); it != coach_out.end(); ++it)
                {
                    if(coach_in.top() == (*it))
                    {
                        coach_in.pop();
                        coach_counter++;
                    }
                }
        
            if(coach_counter == coach_num)
                cout << "Yes" << endl;
            else
                cout << "No" << endl;
        }
    
        cout << endl;
    }
    
    return 0;
}