poj 1363 Rails

Time Limit: 1000MS		Memory Limit: 10000K
Total Submissions: 13192		Accepted: 5312

一道题很简单在很多的oj上都有这样的题目，利用栈的方法很容易解决，因为只有栈顶的元素才能出栈，这与本题的模型一样，所以采用栈的方法

代码：

 

  
    

   
     
   
      1 
   
     #include
   
     <
   
     stdio.h
   
     >
   
     

   
      2 
   
     #include
   
     <
   
     stack
   
     >
   
     

   
      3 
   
      
   
     using
   
      
   
     namespace
   
      std;

   
      4 
   
      
   
     int
   
      main()

   
      5 
   
     {

   
      6 
   
      
   
     int
   
      cur,i,j,a,n,mark;

   
      7 
   
      
   
     while
   
     (scanf(
   
     "
   
     %d
   
     "
   
     ,
   
     &
   
     n)
   
     !=
   
     EOF)

   
      8 
   
      {

   
      9 
   
      
   
     if
   
     (n
   
     ==
   
     0
   
     )

   
     10 
   
      
   
     break
   
     ;

   
     11 
   
      
   
     while
   
     (
   
     1
   
     )

   
     12 
   
      {

   
     13 
   
      stack
   
     <
   
     int
   
     >
   
      st;

   
     14 
   
      i
   
     =
   
     1
   
     ;st.push(i);

   
     15 
   
      mark
   
     =
   
     0
   
     ;

   
     16 
   
      
   
     for
   
     (j
   
     =
   
     1
   
     ;j
   
     <=
   
     n;j
   
     ++
   
     )

   
     17 
   
      {

   
     18 
   
      scanf(
   
     "
   
     %d
   
     "
   
     ,
   
     &
   
     a);

   
     19 
   
      
   
     if
   
     (a
   
     ==
   
     0
   
     )

   
     20 
   
      {

   
     21 
   
      mark
   
     =
   
     1
   
     ;

   
     22 
   
      
   
     break
   
     ;

   
     23 
   
      }

   
     24 
   
      
   
     if
   
     (st.empty())

   
     25 
   
      {

   
     26 
   
      i
   
     ++
   
     ;

   
     27 
   
      st.push(i);

   
     28 
   
      }

   
     29 
   
      cur
   
     =
   
     st.top();

   
     30 
   
      
   
     while
   
     (cur
   
     !=
   
     a)

   
     31 
   
      {

   
     32 
   
      
   
     if
   
     (i
   
     ==
   
     n)

   
     33 
   
      
   
     break
   
     ;

   
     34 
   
      i
   
     ++
   
     ;

   
     35 
   
      st.push(i);

   
     36 
   
      cur
   
     =
   
     st.top();

   
     37 
   
      }

   
     38 
   
      
   
     if
   
     (cur
   
     ==
   
     a)

   
     39 
   
      st.pop();

   
     40 
   
      }

   
     41 
   
      
   
     if
   
     (mark)

   
     42 
   
      
   
     break
   
     ;

   
     43 
   
      
   
     if
   
     (st.empty())

   
     44 
   
      printf(
   
     "
   
     Yes\n
   
     "
   
     );

   
     45 
   
      
   
     else
   
     

   
     46 
   
      printf(
   
     "
   
     No\n
   
     "
   
     );

   
     47 
   
      }

   
     48 
   
      printf(
   
     "
   
     \n
   
     "
   
     );

   
     49 
   
      }

   
     50 
   
      
   
     return
   
      
   
     0
   
     ;

   
     51 
   
     }

   
     52