ZOJ 1259 Rails

stack的应用

 #include<iostream>
 #include<cstdio>
 #include<stack>
 using namespace std;
 int goal[];
 int d[];
 stack<int>s;
 int main()
 {
     freopen("input.txt","r",stdin);
     int n;
     for(int i = ; i <= ; i++)
         d[i] = i;
     while(cin>>n && n)
     {
         while(cin>>goal[] && goal[])
         {
             while(!s.empty())
                 s.pop();
             for(int i = ; i <= n; i++)
                 cin>>goal[i];
             int i = ;
             int pos = ;
             s.push(d[]);
             while(pos <= n && i <= n+)
             {
                 if(s.empty() || s.top() != goal[pos])
                 {
                     s.push(d[i]);
                     i++;
                 }
                 else if(s.top() == goal[pos])
                 {
                     s.pop();
                     pos++;
                 }
                 else break;
             }
             if(s.empty())
                 cout<<"Yes"<<endl;
             else cout<<"No"<<endl;

         }
         cout<<endl;
     }
     return ;
 }