STL-栈&队列FIFO,FILO

#include<iostream>#include<cstdio>#include<string>#include<queue>#include<stack>#include<algorithm>#include<cmath>#include<list>#include<cstdlib>#include<cstring>using namespace std;int main(){ int t; cin>>t; while(t--){ int n; cin>>n; string s1,s2; cin>>s1; if(s1=="FIFO"){ queue<int>qu; while(n--){ cin>>s2; if(s2=="IN"){ int num; cin>>num; qu.push(num); }else{ if(qu.empty()){ cout<<"None"<<endl; }else{ cout<<qu.front()<<endl; qu.pop(); } } } }else{ stack<int>st; while(n--){ cin>>s2; if(s2=="IN"){ int num; cin>>num; st.push(num); }else{ if(st.empty()){ cout<<"None"<<endl; }else{ cout<<st.top()<<endl; st.pop(); } } } } } return 0;}