I don't know!

#include<bits/stdc++.h>
using namespace std;
long long t,n,a[200005],a1,a2,v;
int main(){
cin>>t;
while(t--){
cin>>n;
a1=a2=-10000000000;
v=0;
for(int i=1;i<=n;i++){
cin>>a[i];
}
for(int i=1;i<=n;i++){
if(a1<a2)swap(a1,a2);
if(a[i]>=a1)a1=a[i];
else if(a[i]>=a2)a2=a[i];
else v=1;
}
if(!v)cout<<"YES\n";
else cout<<"NO\n";
}
}