这就是简单双端对列模板
#include"bits/stdc++.h"
using namespace std;
deque<int>d;
vector<int>v;
int t,n,x;
int main()
{
cin >> t;
while(t--)
{
v.clear();
d.clear();
cin >> n;
for(int i=1;i<=n;i++){
cin >> x;
v.push_back(x);
}
for(int i=0 ; i < n ; i++){
if(d.empty()){
d.push_back(v[i]);
}else if(d.size() == 1){
if(v[i] > d.front()){
d.push_back(v[i]);
}else{
d.push_front(v[i]);
}
}
else{
int a = d.front();
int b = d.back();
if(v[i] < a){
d.push_front(v[i]);
}else{
d.push_back(v[i]);
}
}
}
for(auto i : d){
cout << i << " ";
}
cout << endl;
}
return 0;
}