基础队列和栈的应用

ACboy needs your help again!

Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 4832    Accepted Submission(s): 2473

Problem Description

ACboy 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!

 

Input

The 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.

 

Output

For 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 Input

44 FIFOIN 1IN 2OUTOUT4 FILOIN 1IN 2OUTOUT5 FIFOIN 1IN 2OUTOUTOUT5 FILOIN 1IN 2OUTIN 3OUT

 

Sample Output

122112None2

3

提交用C++AC，用G++就WA了，基本的队列和栈的操作，基础题。

[cpp] view plain copy

1. #include<stdio.h>  
2. #include<stack>  
3. #include<queue>   
4. using namespace std;  
5. int main()  
6. {  
7.     char s[4];  
8.     int test,n,k;  
9.     scanf("%d",&test);  
10.     while(test--)  
11.     {  
12.         scanf("%d %s",&n,s);  
13.         if(s[2]=='F')  
14.         {  
15.             queue<int> b;  
16.             while(n--)  
17.             {  
18.                 scanf("%s",s);  
19.                 if(s[0]=='I')  
20.                 {  
21.                     scanf("%d",&k);  
22.                     b.push(k);  
23.                 }  
24.                 else if(b.empty())  
25.                     printf("None\n");  
26.                 else{     
27.                     printf("%d\n",b.front());  
28.                     b.pop();  
29.                 }  
30.             }  
31.         }  
32.         else  
33.         {  
34.             stack<int> a;  
35.             while(n--)  
36.             {  
37.                 scanf("%s",s);  
38.                 if(s[0]=='I')  
39.                 {  
40.                     scanf("%d",&k);  
41.                     a.push(k);  
42.                 }  
43.                 else if(a.empty())  
44.                     printf("None\n");  
45.                 else{  
46.                     printf("%d\n",a.top());  
47.                     a.pop();  
48.                 }   
49.             }  
50.         }  
51.     }  
52. }