hdu1702 list or stack+queue

http://acm.hdu.edu.cn/showproblem.php?pid=1702

#include<iostream>
#include<cstdio>
#include<cstring>
#include<list>
using namespace std;
int main()
{
   // freopen("1.txt","r",stdin);
    int n;
    scanf("%d",&n);
    while(n--)
    {
        int m,i,x;
        list<int>li;
        li.clear();
        char s[10],ss[10];
        scanf("%d %s",&m,s);
        if(strcmp(s,"FIFO")==0)
        {
            for(i=0; i<m; i++)
            {
                scanf("%s",ss);
                if(strcmp(ss,"IN")==0)
                {
                    cin>>x;
                    li.push_back(x);
                }
                else
                {
                    if(li.empty())
                        cout<<"None"<<endl;
                    else
                    {
                        cout<<li.front()<<endl;
                        li.pop_front();
                    }
                }
            }
        }
        else
        {
            for(i=0; i<m; i++)
            {
                scanf("%s",ss);
                if(strcmp(ss,"IN")==0)
                {
                    cin>>x;
                    li.push_back(x);
                }
                else
                {
                    if(li.empty())
                        cout<<"None"<<endl;
                    else
                    {
                        cout<<li.back()<<endl;
                        li.pop_back();
                    }
                }
            }
        }
    }
    return 0;
}

　　

#include<iostream>
#include<cstdio>
#include<cstring>
#include<stack>
#include<queue>
using namespace std;
int main()
{
   // freopen("1.txt","r",stdin);
    int n,x,m;
    char s[10],ss[10];
    stack<int>st;
    queue<int>q;
    scanf("%d",&n);
    while(n--)
    {
        while(!st.empty())
            st.pop();
        while(!q.empty())
            q.pop();
        scanf("%d %s",&m,s);
        if(strcmp(s,"FILO")==0)
        {
            for(int i=0; i<m; i++)
            {
                scanf("%s",ss);
                if(strcmp(ss,"IN")==0)
                {
                    cin>>x;
                    st.push(x);
                }
                else
                {
                    if(st.empty())
                        cout<<"None"<<endl;
                    else
                    {
                        cout<<st.top()<<endl;;
                        st.pop();
                    }
                }
            }
        }
        else
        {
            for(int i=0; i<m; i++)
            {
                scanf("%s",ss);
                if(strcmp(ss,"IN")==0)
                {
                    cin>>x;
                    q.push(x);
                }
                else
                {
                    if(q.empty())
                        cout<<"None"<<endl;
                    else
                    {
                        cout<<q.front()<<endl;
                        q.pop();
                    }
                }
            }
        }
    }
    return 0;
}