F

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!

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 Input

4
4 FIFO
IN 1
IN 2
OUT
OUT
4 FILO
IN 1
IN 2
OUT
OUT
5 FIFO
IN 1
IN 2
OUT
OUT
OUT
5 FILO
IN 1
IN 2
OUT
IN 3
OUT

Sample Output

1
2
2
1
1
2
None
2
3

题意讲的很清楚，就是用栈和队列来模拟，但是提交的时候WA了两次，后来才发现当进入过一组数据后，要把栈和队列清空

AC代码

#include<iostream>
#include<cstdio>
#include<cstring>
#include<stack>
#include<queue>
const int maxn = 1000;

using namespace std;

int main()
{
    stack<int> sT;
    queue<int> que;

    int t, num;
    char xx[5];
    char s1[3] = "IN", s2[4] = "OUT";
    char s3[5] = "FIFO", s4[5] = "FILO";

    scanf("%d", &t);

    while(t--)
    {
        int n;
        char str[5];

        scanf("%d %s", &n, &str);

        if(strcmp(str, s3) == 0)
        {
            for(int i = 0; i < n; i++)
            {
                scanf("%s", &xx);

                if(strcmp(xx, s1) == 0)
                {
                    scanf("%d", &num);
                    que.push(num);
                }

                if(strcmp(xx, s2) == 0)
                {
                    if(que.empty())
                    {
                        printf("None
");
                    }

                    else
                    {
                        printf("%d
", que.front());
                        que.pop();
                    }
                }
            }

            while(!que.empty())
                que.pop();
        }

        if(strcmp(str, s4) == 0)
        {
            for(int i = 0; i < n; i++)
            {
                scanf("%s", &xx);

                if(strcmp(xx, s1) == 0)
                {
                    scanf("%d", &num);
                    sT.push(num);
                }

                if(strcmp(xx, s2) == 0)
                {
                    if(sT.empty())
                    {
                        printf("None
");
                    }
                    else
                    {
                        printf("%d
", sT.top());
                        sT.pop();
                    }
                }
            }

            while(!sT.empty())
                sT.pop();
        }
    }
    return 0;
}

在网上找了一些其他人的代码，发现也有人用vector来解题，也要学习一下

/*
题意：这个东西总共两种模式：栈和队列，然后模拟

解体思路：既然是模拟，就没什么搞得了。开搞

*/
#include<bits/stdc++.h>
using namespace std;
int t,n;
int a;
string op,name;
vector<int>v;
void init(){
    v.clear();
}
int main(){
    //freopen("in.txt","r",stdin);
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        cin>>name;
        init();
        if(name=="FIFO"){//先进先出
            for(int i=0;i<n;i++){
                cin>>op;
                if(op=="IN"){//进入
                    scanf("%d",&a);
                    v.push_back(a);
                }else{//出
                    if(v.size()==0){
                        printf("None
");
                    }else{
                        printf("%d
",v[0]);
                        v.erase(v.begin());
                    }
                }
            }
        }else{//先进后出
            for(int i=0;i<n;i++){
                cin>>op;
                if(op=="IN"){//进入
                    scanf("%d",&a);
                    v.push_back(a);
                }else{//出
                    if(v.size()==0){
                        printf("None
");
                    }else{
                        printf("%d
",v[v.size()-1]);
                        v.erase(v.end()-1);
                    }
                }
            }
        }
    }
    return 0;
}