数据结构--数组模拟队列

 1 #include<iostream>
 2 using namespace std;
 3 const int N=1e5+10;
 4 int m;
 5 int head=0,tail=-1;
 6 int q[N];
 7 int main(void){
 8     int m;
 9     cin>>m;
10     for(int i=0;i<m;i++){
11         string op;
12         int x;
13         cin>>op;
14         if(op=="push"){
15             cin>>x;
16             q[++tail]=x;
17         }else if(op=="pop"){
18             head++;
19         }else if(op=="empty"){
20             if(tail<head){
21                 cout<<"YES"<<endl;
22             }else{
23                 cout<<"NO"<<endl;
24             }
25         }else if(op=="query"){
26             cout<<q[head]<<endl;
27         }
28     }
29     return 0;
30 }