HDU 1702 ACboy needs your help again! (棧和隊列的類比)

標籤：des   style   blog   http   color   java   os   io   

ACboy needs your help again!

Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3164    Accepted Submission(s): 1655

Problem DescriptionACboy was kidnapped!! 
he miss his mother very much and is very scare now.You can‘t image how dark the room he was put into is, so poor :(.
As a smart ACMer, you want to get ACboy out of the monster‘s labyrinth.But when you arrive at the gate of the maze, the monste say :" I have heard that you are very clever, but if can‘t solve my problems, you will die with ACboy."
The problems of the monster is shown on the wall:
Each problem‘s first line is a integer N(the number of commands), and a word "FIFO" or "FILO".(you are very happy because you know "FIFO" stands for "First In First Out", and "FILO" means "First In Last Out").
and the following N lines, each line is "IN M" or "OUT", (M represent a integer).
and the answer of a problem is a passowrd of a door, so if you want to rescue ACboy, answer the problem carefully! 

 

InputThe input contains multiple test cases.
The first line has one integer,represent the number oftest cases.
And the input of each subproblem are described above. 

 

OutputFor each command "OUT", you should output a integer depend on the word is "FIFO" or "FILO", or a word "None" if you don‘t have any integer. 

 

Sample Input44 FIFOIN 1IN 2OUTOUT4 FILOIN 1IN 2OUTOUT5 FIFOIN 1IN 2OUTOUTOUT5 FILOIN 1IN 2OUTIN 3OUT 

 

Sample Output122112None23 

 

Source2007省賽集訓隊練習賽（1） 

 

Recommendlcy 

 就是對棧和隊列的類比，棧是FILO隊列是FIFO

 1 #include<iostream> 2 #include<cstdio> 3 #include<queue> 4 #include<stack> 5 #include<string> 6 using namespace std; 7 int main() 8 { 9     int kase,n,num;10     string s,str;11     cin>>kase;12     while(kase--)13     {14         cin>>n>>s;15         if(s=="FIFO")16         {17             queue<int> Q;18             while(n--)19             {20                 cin>>str;21                 if(str=="IN")22                 {23                     cin>>num;24                     Q.push(num);25                 }26                 if(str=="OUT")27                 {28                     if(Q.empty())29                         printf("None\n");30                     else31                     {32                         printf("%d\n",Q.front());33                         Q.pop();34                     }35                 }36             }37         }38         if(s=="FILO")39         {40             stack<int> S;41             while(n--)42             {43                 cin>>str;44                 if(str=="IN")45                 {46                     cin>>num;47                     S.push(num);48                 }49                 if(str=="OUT")50                 {51                     if(S.empty())52                         printf("None\n");53                     else54                     {55                         printf("%d\n",S.top());56                         S.pop();57                     }58                 }59             }60         }61     }62     return 0;63 }

View Code